The present invention generally relates to a heat dissipation device for removing heat from an electronic component and particularly to a heat dissipation device which has a heat capacitor for storing heat received from the electronic component.
With advancement of computer technology, electronic devices operate with high speeds. It is well known that more rapidly the electronic devices operate, more heat they generate. If the heat is not dissipated duly, the stability of the operation of the electronic devices will be impacted severely.
Generally, in order to ensure the electronic device to run normally, a heat dissipation device is used to dissipate the heat generated by the electronic device.
However, when a suddenly high power surges through the heat-generating electronic component, it generates a suddenly large amount of heat. The suddenly increased large amount of heat, though appearing only for an instant, cannot be timely dissipated via the heat dissipation device. Accordingly, a suddenly high temperature of the heat-generating electronic component is caused. The suddenly high temperature of the heat-generating electronic component is possible to exceed its normal working temperature. When this happens, the heat-generating electronic component could be damaged and its lifespan could be affected. It is significant to enable the heat-generating electronic component to be held at a constant working temperature range, such that the heat-generating electronic component can avoid the damage or even malfunction due to the abrupt temperature raise because of the suddenly high power surge. Consequently, there is a need to provide a heat dissipation device that can quickly absorb the suddenly increased heat of the heating-generating electronic component to maintain the temperature of the heat-generating electronic component temperature within a predetermined range.
A heat dissipation device in accordance with a preferred embodiment of the present invention comprises a heat sink and a heat capacitor attached on the heat-absorbing portion. The heat sink comprises a base attachable with a heat-generating electronic component and a fin assembly extending from the base. The fin assembly comprises two supports and each support comprises a plurality of fins extending in different directions. The heat capacitor comprises a sealed container made of a material with a high heat conductivity and a heat-storing material made of a phase-change thermal interface material and received in the container. The heat-storing material changes from solid state to liquid state upon receiving heat from the heat-generating electronic component, and from the liquid state to the solid state after releasing the heat.
Other advantages and novel features will become more apparent from the following detailed description of preferred embodiments when taken in conjunction with the accompanying drawings, in which:
Referring to
The heat capacitor 20 is attached to the base 12 and received in the groove 16 by soldering means or by other conventional means such that a bottom surface of the heat capacitor 20 is thermally contacted with the top surface of the base 12 at a bottom extremity of the groove 16. The heat capacitor 20 is located just above the heat-generating electronic component 30. The heat capacitor 20 comprises a cubical container 22, a heat-storing material 24 accommodated in the container 22 and a cover 26 sealing a top opening of the container 22. The container 22 is preferably made of a metal with a high heat conductivity, such as aluminum or copper. The heat-storing material 24 is made of a phase-change material having a lower melting point, capable of changing from solid state to liquid state by absorbing heat from the heat-generating electronic component 30 and returning back to the solid state by releasing the heat stored therein. In the preferred embodiment, the heat-storing material 24 is a phase-change thermal interface material (TIM) sold by Bergquist company with a part name of Hi-Flow 225U or by Honeywell company with a part name of PCM45 Series Phase Change Thermal Interface Material.
When a high power suddenly surges through it, the heat-generating electronic component 30 produces excessive heat than normally expected; the heat capacitor 20 can quickly absorb the excessive heat which can not be duly dissipated out by the heat sink 10 and store the heat therein to maintain the temperature of the heat-generating electronic component 30 within an acceptable level. When the heat-generating electronic component 30 is returned to a normal operation or an idle and the heat generated by the heat-generating electronic component 30 is decreased, the heat sink 10 is available to absorb the excessive heat from the heat capacitor 20 and release the excessive heat to an ambient environment. Thus, the temperature of the heat-generating electronic component 30 can be maintained in a stable range.
In operation, when the heat generated by the heat-generating electronic component 30 exceeds a specified level, it is first transferred to the bottom of the base 12. A part of the heat on the base 12 is directly transferred to the supports 140 and then to the first and second fins 142, 144. The heat in the fin assembly 14 is dissipated along different directions perpendicular and parallel to the base 12. Another part of the heat is transferred to the heat capacitor 20 and absorbed by and stored in the heat-storing material 24 of the heat capacitor 20. Since the heat-storing material changes phase upon absorbing the heat, a large portion of the heat generated by the heat-generating electronic component 30 is conveyed to the heat capacitor 20. Accordingly the heat-generating electronic component 30 is cooled quickly and its temperature is stably maintained within a predetermined range.
It is believed that the present embodiments and their advantages will be understood from the foregoing description, and it will be apparent that various changes may be made thereto without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the examples hereinbefore described merely being preferred or exemplary embodiments of the invention.