Dual In-line Memory Module Research Articles

A strategy for improvement of the C<SUB align=right>pk of DRAM modules in the depanel process of PCBA

This paper is to improve the dimensional accuracy of Small Outline Dual Inline Memory Modules (SO-DIMMs), which is a kind of Dynamic Random Access Memory (DRAM) modules for notebook computer, in the depanel process. This study proposes the implementation of combining grey relation analysis with Statistical Process Control (SPC) analysis, so as to quickly search the result that progressive tool wear is the dominant parameters adversely influencing the accuracy in the depanel process. To resolve tool wear issue, this paper implements the pretreated milling for a certain working distance before practically proceeding the depanel process. The accuracy of products, therefore, appears to be feasibly controllable. Furthermore, this study adopts SPC analysis to evaluate the improvement effect, revealing that Cpk value dramatically increases from 0.788 to 2.175, and the tool life of mill can also be extended from milling of 25 to 45 panels. It has also been successfully implemented in an international factory, resulting in a yield of more than 1 million DRAM modules.

Memory subsystem technology and design for the z990 eServer

This paper discusses the technology and design of the first double data rate (DDR) memory subsystem for the IBM zSeries® eServer™. The main storage subsystem accommodates the frequency mismatch between the memory controller and industry-standard synchronous dynamic random-access memory (SDRAM), protects data through error-correction code and SDRAM sparing, and increases overall memory subsystem bandwidth. Each memory card consists of the first synchronous memory interface (SMI) application-specific integrated circuit (ASIC) that is optimized specifically for DDR applications, the SMI-enhanced (SMI-E). The SMI-E controller data interface communicates with the high-speed memory controller on the multichip module through special phase alignment and elastic buffering circuitry that determines the optimal sampling point to reliably receive data from the controller. The SMI-E memory data interface is connected to registered DDR dual inline memory modules running up to 250 Mb/s using 256-Mb and 512-Mb SDRAM technology, thereby allowing memory card densities between 4 GB and 32 GB per card. Because of the increased DDR memory interface bit rates, special attention was paid to the design of the SMI-E substrate and base card to minimize noise. The memory, when used in a fully populated system, has four times more storage capacity than the previous z900 generation.

Bacteriorhodopsin

Discusses how bacteriorhodopsin is a revolutionary material in the battle to bring computing down to the molecular level. Amazing advances can be made by using this protein in three-dimensional optical memory. A five cubic centimeter volume of bacteriorhodopsin studded polymer could theoretically store 512 gigabytes of information. Whereas a 36 cubic centimeter DIMM (dual in-line memory module) currently can only hold 64 megabytes.