TWI492341B - Phase change type heat dissipating device - Google Patents

Description

Phase change heat sink

The invention relates to a heat dissipating device, in particular to a heat dissipating device for dissipating heat generated by an electronic component by using a phase change principle.

In recent years, electronic technology has developed rapidly. The high-frequency, high-speed operation of electronic components and the intensive and miniaturization of integrated circuits have caused electronic components to continuously generate heat during operation. Therefore, it is necessary to attach a heat sink to the electronic components to The heat generated by the components is taken away to ensure stable operation of the electronic components.

The conventional heat dissipation method is to provide a metal heat sink above the heat-generating electronic component, the heat sink has a base, the lower surface of the base is in contact with the electronic component, and the upper surface is provided with a plurality of heat-dissipating fins, and the base absorbs the electrons. The heat generated by the component is transferred to the heat sink fins, which dissipate heat into the surrounding air. However, for some intermittent high-load operation electronic devices, the high-load operation time is short, and the standby or low-load operation time is relatively long. Therefore, the heat generated by the heating elements during the high-load operation of the electronic device will be It is transmitted to the air in the outer casing of the electronic device through the heat dissipation fins in a short time, so that the temperature of the outer casing is too high in a short time, so that the staff can feel uncomfortable during operation; and the heat is generated during standby or low load operation. The component generates less heat and does not cause the temperature of the outer casing to rise, and the heat sink fins are not fully utilized. Therefore, further improvement is needed.

The invention aims to provide a phase change heat dissipating device which avoids excessive temperature of the outer casing when the electronic device is operated under high load and has high utilization efficiency when the electronic device operates under low load.

A phase change heat dissipating device for dissipating heat to a heat generating component, comprising a cavity and a working medium disposed in the cavity, the working medium being a phase change insulating substance exhibiting a solid state at a normal temperature, the cavity housing The heating element is described.

Compared with the prior art, the cavity of the phase change heat dissipating device of the present invention covers the heat generating component, and the working medium in the cavity is a phase change substance which exhibits solid state at normal temperature. During high-load operation, the heat generated by the heating element is first transferred to the working medium, causing the working medium to liquefy to temporarily store heat, slowing the conduction of heat from the inside of the electronic device to the outer casing, so that the surface of the heating element is maintained at In the lower range, the temperature of the outer casing of the electronic device is prevented from rising too fast; when the heating element is in standby or low-load operation, the working medium gradually cools down to release heat, and the working medium continues to transfer and exchange heat, and the utilization efficiency is utilized. Higher.

The phase change heat sink of the present invention will be further described in detail below with reference to the accompanying drawings.

Referring to FIG. 1 to FIG. 3, a phase change heat dissipation device 10 according to a preferred embodiment of the present invention is configured to dissipate heat from a heat generating component 20 in an electronic device (not shown), and includes an upper cover 11 and the upper cover. 11 opposite lower cover 12 and working medium 30 disposed between the upper cover 11 and the lower cover 12.

Specifically, the upper cover 11 and the lower cover 12 are substantially in the shape of a flat plate, and the upper cover 11 is slightly larger in size than the lower cover 12. The peripheral edge of the lower cover 12 extends upward to form a side wall 13 , and the upper edge of the side wall 13 is bent outward to form a side wall. Upper end 131. The edge of the upper cover 11 abuts against the upper end 131 of the side wall to cooperate with the lower cover 12 to form a sealed cavity 14. The upper cover 11, the lower cover 12 and the side wall 13 are made of a material having better conductivity, such as aluminum or copper. It can be understood that the upper cover 11 and the lower cover 12 can be an outer casing of an electronic device or a plate of other components (not shown) inside the electronic device.

The working medium 30 is disposed in the cavity 14. The working medium 30 is an insulating material that exhibits a solid state at a normal temperature, and can be liquefied into a liquid under a certain temperature environment. The working medium 30 is a phase change material, and the melting point thereof The surface temperature of the heating element 20 during standby/low-load operation and the maximum temperature that the heating element 20 can withstand during high-load operation, such as crystalline hydrated salts, organic acids or esters, and the like.

In operation, the heating element 20 is electrically connected to other components in the electronic device by a printed circuit board or a wire, and the cavity 14 is configured to receive the heating element 20. In the embodiment, the heating element 20 is located. The lower cover 12 is on. In operation, the heating element 20 generates heat and rapidly transfers heat to the working medium 30. The working medium 30 near the heating element 20 is gradually liquefied due to being closest to the heat source, and then generates heat convection so as to be relatively far from the heating element 20, adjacent to the cavity 14. The working medium 30 of the inner wall is also gradually liquefied. Finally, when all the working medium 30 becomes liquid, heat can be transferred to the inner wall of the cavity 14, thereby achieving the effect of transient heat storage, and the heat is relieved from being conducted inside the electronic device. The speed to the outer casing ensures that the surface of the heat generating component 20 is maintained in a relatively low temperature range, and the temperature rise of the outer casing of the electronic device is prevented from being excessively fast, thereby reducing the discomfort of the worker during operation. When the electronic device is in standby or low-load operation, so that the heating capability of the heating element 20 is less than the heat dissipation capability of the external casing to the outside, the working medium 30 gradually cools down and releases heat, thereby gradually solidifying to the solid state for the next transient heat storage. To use the loop. During the above-mentioned high-load operation and standby/low-load operation, the working medium 30 is performing heat transfer and exchange, and the working medium 30 is used as a heat dissipating medium with high efficiency. Due to the insulation of the working medium 30, it does not affect the operational characteristics of the heat generating element 20 while causing the surface temperature of the heat generating element 20 to be uniformly lowered.

It can be understood that when the heating element 20 is equipped with a circuit board (not shown), the circuit board can be received in the cavity 14. The upper cover 11 and the lower cover 12 are not limited to a flat plate shape, and may have other shapes such as a triangular prism shape. The shape of the working medium 30 can be changed according to the shape of the forming cavity 14 as long as it is accommodated in the cavity 14.

Compared with the prior art, the cavity 14 of the phase change heat dissipation device 10 of the present invention accommodates the heat generating component 20, and the working medium 30 in the cavity 14 is a phase change insulating material which exhibits a solid state at normal temperature. Therefore, the working medium 30 can be directly in contact with the heating element 20. During high-load operation, the heat generated by the heating element 20 is directly transferred to the working medium 30, causing the working medium 30 to be liquefied to temporarily store heat and reduce heat. The speed of conduction from the inside of the electronic device to the outer casing is such that the surface of the heating element 20 is maintained in a lower range while avoiding excessive temperature rise of the outer casing of the electronic device; when the heating element 20 is in standby or under low load operation The working medium 30 gradually cools down to release heat, and the working medium 30 continues to transfer and exchange heat, and the utilization efficiency is high.

In summary, the present invention complies with the requirements of the invention patent and submits a patent application according to law. The above description is only the preferred embodiment of the present invention, and equivalent modifications or variations made by those skilled in the art will be included in the following claims.

10. . . Phase change heat sink

20. . . Heating element

11. . . Upper cover

12. . . lower lid

13. . . Side wall

131. . . Upper end of side wall

14. . . Cavity

30. . . Working medium

1 is a perspective view of a phase change heat sink according to an embodiment of the invention.

2 to 1 is an exploded perspective view of the phase change heat sink.

3 is a schematic cross-sectional view of the phase change heat sink of FIG. 1.

20. . . Heating element

11. . . Upper cover

12. . . lower lid

13. . . Side wall

131. . . Upper end of side wall

14. . . Cavity

30. . . Working medium

Claims (6)

A phase change heat dissipating device for dissipating heat from a heat generating component, comprising a cavity and a working medium disposed in the cavity, wherein the working medium is a phase change insulating material exhibiting a solid state at a normal temperature, The cavity houses the heating element, and the working medium is a crystalline hydrated salt, an organic acid or an ester, etc., and the melting point of the working medium is different from the surface temperature of the heating element during standby/low-load operation and the high-load operation of the heating element Between the highest temperatures that can withstand. The phase change heat sink of claim 1, wherein the heat generating component is electrically connected to an external power source by a printed circuit board or a wire. The phase change heat sink of claim 2, wherein the heat generating component is provided with a printed circuit board, and the printed circuit board is housed in the cavity. The phase change heat dissipating device of claim 1, wherein the method comprises an upper cover and a lower cover opposite to the upper cover, the working medium being disposed between the upper cover and the lower cover. The phase change heat dissipating device of claim 4, wherein the lower cover peripheral edge is bent upward to form a side wall, and the upper cover edge abuts against the lower end of the side wall to cooperate with the lower cover to form the cavity. The phase change heat sink of claim 4, wherein the heat generating component is located on the lower cover.