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Method for a high-performance memory module with integrated package stacking and an embedded heat spreader

IP.com Disclosure Number: IPCOM000101568D
Publication Date: 2005-Mar-16
Document File: 6 page(s) / 230K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method for high-performance memory module with integrated package stacking and an embedded heat spreader. Benefits include improved functionality, improved performance, and improved design flexibility

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Method for a high-performance memory module with integrated package stacking and an embedded heat spreader

Disclosed is a method for  high-performance memory module with integrated package stacking and an embedded heat spreader. Benefits include improved functionality, improved performance, and improved design flexibility.

Background

              Dynamic random access memory (DRAM) and synchronous dynamic random access memory (SDRAM) technologies are contributing to improved computer system performance. Unsatisfied with the conventional concept of

Moore

’s law, original equipment manufacturers (OEMs) require packaging solutions that increase memory capacity without the accumulation of additional modules to avoid system-level space constraints. With the increased consumer demand on smaller and smaller system form factors and higher overall system performance, high memory density is increasingly becoming a serious packaging challenge.

              Conventionally, the stacking of memory semiconductor die or semiconductor packages is a common method for increasing memory capacity (see Figure 1). However, with increased memory device power, thermal management is an additional issue (see Figure 2). Stacking technology utilizes low-power devices and finished device packaging. When the DRAM memory power surpasses a certain level, thermal management becomes a problem.

General description

              The disclosed method enlarges the DRAM package interposer size and integrates the DRAM into the printed circuit board (PCB) module for signal routing flexibility. The method uses polymer material between stack layers for thermoelectric cooler (TEC) mismatch coupling and mechanical shock absorbing. An embedded heat spreader provides device protection and heat dissipation/thermal management. By controlling the thickness and size of the heat spreader, the DRAM memory device junction temperature can be evenly controlled to not exceed a designated limit. Additionally, the stacking structure design is scaleable for multiple stacks.

              The key elements of the disclosed method include:

•             An integrated package substrate that is part of a memory PCB module memory interposer subassembly (MIS)

•             Embedded heat spreader that is coupled with thermal interface material (TIM) as part of MIS to improve memory device performance

•             Embedded heat spreader that provides mechanical protection for the bare memory die

•             Embedded heat spreader that is individually designed in terms of thickness and size to provide precise control of the silicon device junction temperature

•             Polymer material that couples the MIS and the MIS and PCB module for mechanical shock absorption and provides resilience for the silicon package to the temperature coefficient of expansion (TCE) mismatch

•             MIS that provides an additional routing layer (or, potentially, reduce the module routing layer) and routing flexibility for a given signa...