Heat dissipation device for at least two electronic devices with two sets of fins

A heat dissipation device for removing heat from an electronic device and electronic components, includes a base plate in contact with the electronic device, a first fin set and a second fin set mounted on the base plate. The first fin set includes a plurality of first fins perpendicularly arranged on the base plate. The second fin set includes a plurality of second fins attached to a lateral side of the first fin set and perpendicular to both the first fins and the base plate. A fan is mounted on tops of the first fin set and the second fin set to cover both of them. Air generated by the fan flows through the first and second fin sets to cool the electronic components mounted on orthogonally neighboring sides of the heat dissipation device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The disclosure relates generally to heat dissipation devices and, more particularly, to a heat dissipation device incorporating a fan and heat pipes for removing heat from an electronic device and other electronic components mounted around the electronic device simultaneously.

2. Description of Related Art

It is well known that during operation computer electronic devices such as central processing units (CPU) generate large amounts of heat. The heat must be quickly removed from the electronic device to prevent it from becoming unstable or being damaged. Typically, a heat sink is attached to an outer surface of the electronic device to absorb heat from the electronic device, and the heat absorbed by the heat sink is then dissipated to ambient air.

Generally, in order to improve heat dissipation efficiency of a heat sink, a fan and heat pipes are incorporated into the heat sink. Usually, the fan is mounted to a top of the heat dissipation device. Conventionally, the heat sink mainly comprises a heat-conducting base for contacting the heat generating electronic device and a plurality of fins arranged on the base, wherein each heat pipe has an evaporating portion embedded in a top face or bottom face of the base and a condensing portion extending through the fins. Typically, the fins are parallel to each other and define a plurality of air passages therebetween. Airflow generated by the fan is blown downwardly into the passages between the fins, and then flows away from the fins via opposite openings of the air passages into two opposite sides of the heat sink, whereby the electronic components located at the two sides of the heat sink are cooled simultaneously by the airflow. Meanwhile, the heat generating electronic device is also cooled. However, the airflow generated by the fan can not reach another two opposite sides of the heat sink, thus other electronic components located at the another two opposite sides of the heat sink can not be cooled properly.

What is needed, therefore, is a heat dissipation device which can cool a main electronic component located under the heat dissipation device and can provide an airflow able to cool electronic components located near neighboring sides of the heat dissipation device simultaneously.

DETAILED DESCRIPTION OF THE INVENTION

FIGS. 1 to 3illustrate a heat dissipation device in accordance with an exemplary embodiment of the present disclosure. The heat dissipation device is provided for removing heat from an electronic device (not shown) and other electronic components (not shown) mounted around the electronic device simultaneously. Particularly, the electronic components are mounted near orthogonally neighboring sides of the heat dissipation device and the electronic device is mounted under the heat dissipation device. The electric device is a central processing unit (CPU), while the electronic components are north bridge chipset and MOSFET. The heat dissipation device comprises a base10, a fin assembly20arranged on the base10, a heat pipe assembly30thermally connecting the base10and the fin assembly20together and a fan assembly40mounted on a top of the fin assembly20.

The base10is made of metallic material with high heat conductivity such as copper or aluminum, and comprises a rectangular base plate12and four fixing legs14extending outwardly from four corners of the base plate12. The base plate12has a bottom surface for contacting the electronic device and a top surface on which the fin assembly20is disposed. A plurality of receiving grooves120are defined in a middle portion of the top surface of the base plate12. The receiving grooves120are spaced from each other and parallel to two opposite lateral sides (i.e., a left and right sides) of the base plate12. A total quantity of the receiving grooves120is consistent with that of heat pipes32,34included in the heat pipe assembly30, and is three in this embodiment. A rectangular recession122is defined in the top surface of the base plate12and extends at a front, left corner of the base plate12. The recession122extends transversely through a front end of a left receiving groove120to a middle of a front end of a middle receiving groove120. Each fixing leg14extends outwards from the corner of the base plate12along a corresponding diagonal direction of the base plate12and defines a mounting hole140therein adjacent to a distal end thereof, for receiving a fixture (not shown) to mount the heat dissipation device onto a printed circuit board on which the electronic device and the electronic components are mounted.

The fin assembly20comprises a first fin set22placed on the top surface of the base plate12and a second fin set24horizontally coupled to a front side of the first fin set22by soldering and located over a front side of the top surface of the base plate12. The second fin set24has a front portion (not labeled) extending forwardly beyond the front side of the top surface of the base plate12. The first fin set22comprises a plurality of first fins220buckling together. The first fins220are spaced from each other with a constant distance, and are perpendicular to both the top surface of the base plate12and the receiving grooves120of the base plate12. The first fins220define a plurality of first air passages therebetween. Each first air passage has two opposite first ends in communication with ambient air at the left and right sides of the first fin set22and a second end at a bottom of the first fin set22. Each first fin220is substantially rectangular and has two opposite end portions extending outwards beyond the base plate12. Each first fin220defines two spaced through holes222therein adjacent to an upper edge thereof and an annular flange224extending perpendicularly from an edge of the through hole222. All of the through holes222and corresponding annular flanges224cooperate with each other to define two parallel first receiving channels (not labeled) which are perpendicular to the first fins220and parallel to the receiving grooves120of the base plate12. Each first fin220has a flange228extending perpendicularly from a middle portion of a lower edge thereof. All of the flanges228cooperate with each other to define a flat contacting surface in contact with the top surface of the base plate12. Three receiving grooves226corresponding to the three receiving grooves120of the base plate12are defined in the contacting surface and cooperate with the three receiving grooves of the base plate12respectively to define three second receiving channels (not labeled).

The second fin set24has a dimension smaller than that of the first fin set22and is coupled to a middle portion of the front lateral side of the first fin set22and located between the two first receiving channels of the first fin set22. The second fin set24comprises a plurality of second fins240vertically arranged on a front portion of the base plate12. The second fins240are perpendicular to the first fins220and have a height equal to that of the first fins220, whereby the fin set assembly20has a flat top surface on which the fan assembly40is mounted. The second fins240define a plurality of second air passages therebeween. Each second fin240has two elongated flanges242extending perpendicular from two opposite sides (i.e., a front and rear sides) thereof. All of the elongated flanges242of the second fins240cooperate with each other to form an inner flat surface attached to the front side of the first fin set22by conventional means such as soldering or adhering, and an outer flat surface parallel to the inner surface. Each second air passage has two first ends sealed by the inner flat surface and the outer flat surface at the front and rear sides of the second fin set24, and a second end at a bottom of the second fin set24. A rectangular cutoff246corresponding to the rectangular recession122of the base plate12is defined in a corner of the bottom of the second fin set24. The cutoff246cooperates with the rectangular recession122of the base plate12to define a receiving space (not labeled). An extending hole244is defined in the second fin set24, perpendicular to the second fins240and located adjacent to a top of the second fin set24and above the rectangular cutoff246.

The heat pipe assembly30comprises two first heat pipes32and a second heat pipe34. Each first heat pipe32is U-shaped and has two parallel horizontal portions322and an arched connecting portion324interconnecting the two horizontal portions322. A lower one of the two horizontal portions322functions as an evaporating portion, while an upper one functions as a condensing portion of the first heat pipe32. In this embodiment, the two first heat pipes32are identical to each other. The second heat pipe34comprises an evaporating portion342, a condensing portion346above and perpendicular to the evaporating portion342and a connecting portion (not labeled) interconnecting the evaporating portion342and the condensing portion346. The connecting portion comprises a linear portion344extending perpendicularly from an end of the evaporating portion342and an arched portion348interconnecting the linear portion344and the condensing portion346, wherein the condensing portion346and the connecting portion are coplanar with each other and located at a vertical plane to which the evaporating portion342is perpendicular.

In assembly of the heat dissipation device, the two lower horizontal portions322of the two first heat pipes32are received in the two lateral ones of the second receiving channels cooperatively formed by the two lateral ones of the receiving grooves120of the base plate12and two lateral ones of the receiving grooves226of the first fin set22. Two upper horizontal portions322of the two first heat pipes32are received in the first receiving channels cooperatively formed by the through holes222and the annular flanges224of the first fins220, while the two connecting portions324of the first heat pipes32are located at the rear side of the fin assembly20opposite to the second fin set24and covered by the rear portion of the fan42. The evaporating portion342of the second heat pipe34is received in the middle one of the second receiving channels formed by the middle one of the receiving grooves120of the base plate12and a middle one of the receiving grooves226of the first fin set22. The condensing portion346of the second heat pipe34is received in the extending hole244of the second fin set24. The connecting portion of the second heat pipe34connects the evaporating portion342and the condensing portion346together, wherein the linear portion344of the connecting portion parallel to the evaporating portion346is accommodated in the receiving space cooperatively defined by the rectangular recession122of the base plate12and the cutoff246of the second fin set24, while the arched portion348of the connecting portion is located at the front side of the first fin set22opposite to the connecting portions324of the first heat pipes32.

In use of the heat dissipation device, heat generated by the electronic device is absorbed by the base plate12, then transferred to the first fin set22directly or indirectly via the first heat pipes32and also transferred to the second fin set24via the second heat pipe34. The heat distributed over the first and second fin sets22,24is finally dissipated into ambient air by an airflow generated by the fan42. One part of the airflow generated by the fan42passes through the first air passages of the first fin set22to reach the two opposite sides (the left and right sides) of the heat dissipation device via the two first ends of the first air passages, and cool one of the electronic components located near one of the left and right sides of the heat dissipation device, while other part of the airflow passes through the second air passages of the second fin set24via the second ends of the second air passages to reach the front side of the heat dissipation device and cool the other one of the electronic components located under the second ends of the second air passages of the second fin set and near the front side of the heat dissipation device. Thus, the electronic components located at orthogonally neighboring sides of the heat dissipation device can be simultaneously cooled by the airflow generated by the fan42of the fan assembly40. In addition, the electronic device contacting a bottom of the base plate12is also cooled.