Thermal Vehicle for Memory Cooling using a Heatsink with Posts and Under-board Plate
Original Publication Date: 2004-Oct-05
Included in the Prior Art Database: 2004-Oct-05
Computer memory subsystems are increasing in density and speed while computer enclosure sizes keep getting smaller for the same number of components; everything contributing to an increasing thermal challenge. Previously, a system with multiple DIMMS hardly needed any direct cooling but, recently, designs have been challenged in the ability to sufficiently cool the memory subsystem. Current solutions to this problem include increasing the air flow with more fans, more expensive fans, limiting the number of DIMMS in the system to increase gap between DIMMS, placing a spreader plate on the module, or limiting a DIMMS bandwidth to cap it's power dissipation. Modern chipsets help distribute this heat load among the populated DIMMS such that they all run cooler. However, a problem occurs when not all of the DIMMS are populated. In fact, the thermal problem at the memory level gets worse with fewer DIMMS, not better even though at the system level there is less total heat. The invention cited extends the spreader plate concept to further improve memory cooling by conducting heat to a larger convective surface.
Thermal Vehicle for Memory Cooling using a Heatsink with Posts and Under -board Plate
Invention consists of a heatsink for a memory DIMM that increases the cooling efficiency that standard cooling spreaders provide. This utilizes underboard space and airflow for heatsink volume by moving the heat through the motherboard using a heatsink with posts. It consists of a memory DIMM that is surrounded by a heat spreader plate (material to be aluminum, copper, or another thermally conductive material), similar to existing solutions, that is thermally coupled to an under-board plate. The spreader plate around the DIMM transports the heat to the thermal dissipation unit under the board, while dissipating small amounts of heat to the air as it moves along it's thermal path. Using Figure 1 as a reference, the memory heat spreader plate is attached to the DRAM components of the DIMM. On the bottom side of the "L" shaped legs of the heat spreader there are posts manufactured into the spreader that are mated with holes in the motherboard. The bottom surface of the posts contacts thermal interface material which is sandwiched between the posts and the under-board plate. To increase heat transfer rate due to free or forced convection of the heat spreader and/or the under-board plate, fins can be added.
Figure 1. Memory Thermal Vehicle using a Heatsink with Posts and Underboard Plate