GB2406442A

GB2406442A - Heat sink

Info

Publication number: GB2406442A
Application number: GB0322365A
Authority: GB
Inventors: Richard Ma
Original assignee: Giga Byte Technology Co Ltd
Current assignee: Giga Byte Technology Co Ltd
Priority date: 2003-09-24
Filing date: 2003-09-24
Publication date: 2005-03-30
Also published as: GB0322365D0; DE20315169U1

Abstract

A heat sink comprises a plurality of fins 310 which are formed with offset pillars 310 to produce a sinuous flow path for air between the fins. The pillars may be of circular, elliptical, square, hexagonal or octagonal cross section.

Description

HEATSINK

The present invention relates to a heat dissipation structure and, in particular, to a heatsink for heat-generating components in electronic devices that are in general accompanied by a side-blowing fan.

Heat dissipation is a major consideration in electronic device design. An electronic device includes many electronic elements. Taking the computer as an example, there are many electronic elements on the motherboard that can generate a tremendous amount of heat during operations. Such elements to include the central processing unit (CPU), the communications chips, the graphics chip, and the dual in-line memory modules (DlMM's). These electronic elements have become much faster than before. For example, the clock frequency of the CPU is now commonly over IGHz, with a heatdissipating power of SOW. If the heat cannot be immediately removed, such electronic elements Is may be overheated to affect their stability and reliability and to shorten their lifetime. Therefore, heat dissipation becomes a serious problem as electronic device frequencies increase.

Currently, electronic device heat dissipation is achieved by heat conduction, convection or radiation to release the generated heat to the environment. A primary means is to use the combination of a heatsink and a fan.

The heatsink is made of metal. It has a heat-conductive base whose bottom is directly installed on the electronic device that generates heat. The heat- conductive base is formed with several heat-dissipating plates to help dissipating heat. The heat produced by the heat-generating electronic device is transferred via the heat-conductive base to the heatdissipating plates. The fan generates airflow through the plates for heat exchange. The heated air is then expelled, taking away the heat from the heat-dissipating plate module and lowering the temperature of the electronic device.

Generally speaking, the heat-dissipation efficiency of the heatsink is so usually determined by its material and structure. The early heatsinks were often made of aluminum because of its small thermal resistance, light weight and low cost. However, as electronic device clock frequencies continuously increase, the heat-dissipation efficiency has to be increased too. Therefore, manufacturers began to use copper as the material for heatsinks. The thermal conduction coefficient of copper is about 1.8 times that of aluminum, while the density of copper is about 3 times that of aluminum. In other words, for heatsinks of the same volume and area, the one made of copper is 3 times heavier than that made of aluminum. Therefore, although a heatsink made of copper has a better thermal conduction coefficient than that made of aluminum; the former is much heavier than the latter. It is therefore necessary to take both the weight and the to thermal conduction coefficient factors into account.

Existing heatsinks on the market are all made of materials with similar compositions. The heat-dissipation efficiencies are also very close. Therefore, increasing heat dissipation by improving the structure has become the main research goal of the manufacturers. For example, the heatdissipating plates are Is usually installed vertically on the base of a heatsink. One of the features of such a vertical heatsink is that the flat plates provide straight airflow channels.

However, the drawbacks of this structure are that the heat-conductive area is too small, that the heat transfer time is too short, and that the parallel airflow cannot provide ideal heat convection after leaving the plates. Even though a layered so structure is provided, there is still scope for improvement.

An object of the present invention is to overcome or alleviate at least some

of the disadvantages of the prior art.

The invention provides a heatsink comprising an array of heat-dissipating plates disposed side by side, the facing surfaces of adjacent plates having complementary recesses and projections which form sinuous airflow paths.

In one embodiment, the heatsink includes: a heat-conductive base and several heat-dissipating plates. The heat-conductive base is installed on a heat- generating component of an electronic device. The heat-dissipating plates are installed vertically at intervals on the heat-conductive base in parallel fashion.

so Each heat-dissipating plate has a flat body and several pillar-like protruding parts distributed thereon. The protruding parts of any two adjacent heat-dissipating l plates do not overlap, forming an airflow space with continuously curved airflow paths.

The pillar-like protruding parts increase the heat dissipation area. With the non-overlapping configuration of the protruding parts between adjacent heat- s dissipating plates, the continuously curved airflow paths thus formed can further Increase the heat transfer efficiency.

The invention will become more fully understood from the non-limiting detailed description of preferred embodiments given hereinbelow by way of example only, wherein: lo Fig. 1 is a three-dimensional view of a first embodiment of the invention; Fig. 2 is a schematic plan view of Fig. 1; Fig. 3 is a schematic local plan view of a second embodiment of the invention; Fig. 4 is a schematic local plan view of a third embodiment of the invention; Fig. 5 is a schematic local plan view of a fourth embodiment of the invention; and Fig. 6 is a schematic local plan view of a fifth embodiment of the invention.

With simultaneous reference to Figs. 1 and 2, the heatsink 100 according no to a preferred embodiment of the invention can be used on heatgenerating devices such as a CPU, communications chips, a graphics chip, and DlMM's, protecting such devices from damage due to overheating.

The heatsink 100 is made of a metal with high thermal conduction coefficients (e.g. aluminum or copper). It consists of a heat-conductive base 200 and several first heat-dissipating plates 300.

The heat-conductive base 200 is formed to fit the shape of a heatgenerating device. Its bottom is attached to the heat-generating device (not shown) for direct contact. A heat-dissipating gel is preferably applied between the heat-conductive base 200 and the heat-generating device, increasing the so thermal conductance of the system.

The heat-dissipating plates 300 are installed vertically at intervals on the top surface of the heat-conductive base 200 (see Fig. 1). Each of the heat- dissipating plates 300 has a flat body with several round pillar-like protruding parts 310 distributed thereon. The heat-dissipating plates 300 can be fixed on the heat-conductive base 200 by gluing or welding. They can also be formed directly by cutting, pressing or extrusion.

All the heat-dissipating plates 300 are equal in length, parallel to one another, and trimmed on the outer side. The protruding parts 310 of any two adjacent heat-dissipating plates 300 do not overlap, forming an airflow space Jo with continuously curved airflow paths in between.

After installing the disclosed heatsink 100 on a heat-generating device, a fan is usually provided on one side (not shown) to produce airflow. The airflow paths are shown in Fig. 2. Since all the heat-dissipating plates 300 have round pillar-like protruding parts, they have a larger heat dissipation area than flat plates and the curved airflow paths increase the duration of heat transfer resulting in better heat dissipation.

In the first embodiment of the invention, if one wants the airflow paths to be specific without any place being too narrow the intervals among the protruding parts 310 on each heat-dissipating plate 300 have to be the same. Therefore, so the protruding parts 310 are distributed in a regular pattern for unifying all airflow paths.

Figs. 3, 4, 5 and 6 are schematic local top views of the second, third, fourth and fifth embodiments of the invention. One may not need round pillar- like protruding parts to achieve continuously curved airflow paths. For instance, elliptical pillars (Fig. 3), octagonal pillars (Fig. 4), hexagonal pillars (Fig. 5), and square pillars (Fig. 6) can all achieve similar effects.

Certain variations would be apparent to those skilled in the art, which variations are considered within the scope of the claimed invention. .

Claims

CLAIMS: 1. A heatsink comprising an array of heat dissipating plates

disposed side by side, the facing surfaces of adjacent plates having complementary recesses and s projections which form sinuous airflow paths.
2. A heatsink comprising: a heat-conductive base, which in use is installed on a heat-generating component of an electronic device; and to a plurality of heat-dissipating plates installed vertically at intervals on the heat-conductive base, each of which has a flat body with a plurality of pillar-like projections, the projections of adjacent heat- dissipating plates being offset to form an airflow space with continuously curved airflow paths in between.

is
3. A heatsink according to claim 1 or claim 2, wherein the projections are elliptical pillars, round pillars, polygonal pillars, octagonal pillars, hexagonal pillars or square pillars aligned with the plates.
4. A heatsink according to any preceding claim, wherein the distance do between any two adjacent projections is the same.
5. A heatsink according to any preceding claim, wherein all of the heat dissipating plates are equal in length.
6. A heatsink according to any preceding claim, wherein the heatdissipating plates are parallel.
7. A heatsink according to any preceding claim, wherein the outer sides of the heat-dissipating plates are trimmed.
8. A heatsink according to any preceding claim, wherein the heatdissipating plates are secured to a heat-conductive base by gluing or welding.
9. A heatsink substantially as described hereinabove with reference to s Figures 1 and 2 of the accompanying drawings, optionally as modified in accordance with any of Figures 3 to 6.