Patent Application
20100150757
1. Field of the Invention
The invention relates to a circuit board adapted to a fan and a fan structure, and, more particularly, to a circuit board that possesses an enhanced efficiency in heat dissipation and a fan structure provided with the same.
2. Description of the Related Art
Generally, a conventional fan is operated by a circuit board to drive a motor for activating a hub and fan blades thereof to generate airflow at a certain speed. Accordingly, the heat generated by a heat-generating device provided with the fan can be dissipated by the airflow.
However, after the fan is operated for a certain period of time, the efficiency in heat dissipation of the fan will deteriorate because during operation the electronic components of the fan also generate heat which cannot be readily dispersed away from the fan structure.
Usually, the integrated circuit of the cooling fan used in a notebook computer operates in a single-phase bipolar mode. In this case, regardless of the amount of operable current of the integrated circuit, since the current flows directly into the integrated circuit, it always results in considerable heat. When the heat cannot be dispersed efficiently, it will accumulate and thus causes problems such as overheating and shutdown of the notebook computer.
In view of the aforementioned problems, an object of the invention is to provide a circuit board adapted to a fan for improving the efficiency in heat dissipation and increasing the operable current range of the electronic components mounted thereon.
Another object of the invention is to provide a fan structure using the aforementioned circuit board for extending the lifetime of a fan.
To achieve the objects, the invention provides a circuit board adapted to a fan comprising a circuit region and a heat-dissipative film. The circuit region is located on one surface of the circuit board and includes a plurality of pads for mounting at least one heat-generating component thereon. The heat-dissipative film is coated on an edge portion of the same surface as the circuit region is located on and is in contact with the heat-generating component.
Preferably, the circuit region is surrounded by the heat-dissipative film, and the heat-dissipative film is formed with a plurality of openings. Besides, the heat-dissipative film is a coating film made of heat-conducting material; specifically, the heat-conducting material is selected from the group consisting of copper, aluminum, iron, and an alloy thereof.
Moreover, the circuit board of the invention may further include a heat sink located on a second surface opposite to the aforementioned surface of the circuit board. Besides, another circuit region may be provided on the second surface of the circuit board. The heat sink is connected to the heat-dissipative film via the openings. The heat sink is formed by coating a heat-conducting material on an edge portion of the second surface; specifically, the heat-conducting material is selected from the group consisting of copper, aluminum, iron, and an alloy thereof.
Furthermore, the circuit board may be provided with a protrusion on which the heat-generating component and/or the heat-dissipative film may be formed. Besides, the protrusion may have a cutout which extends over the length of the heat-generating component.
In addition, the invention also provides a fan structure that includes a hub, a motor located inside the hub, a plurality of fan blades connected to the hub, and a circuit board connected to the motor. Specifically, the fan structure is characterized by the circuit board, which comprises a circuit region and a heat-dissipative film. In more detail, the circuit region is located on one surface of the circuit board and has at least one heat-generating component mounted thereon. The heat-dissipative film is coated on an edge portion of the same surface as the circuit region located on and is in contact with the heat-generating component.
The circuit board of the invention is provided with the heat-dissipative film and optionally the heat sink, thus the heat generated by the heat-generating component can be readily dissipated by the heat-dissipative film or the heat sink, so that it is possible to dramatically enhance the efficiency in heat dissipation.
Also, according to the fan structure of the invention, the heat-dissipative film and/or the heat sink may extend outside the circumference of the hub, thus the heat dissipated from the heat-dissipative film and/or the heat sink can be further dispersed by an airflow generated by the fan. Therefore, it is possible not only for the circuit board to have an enhanced efficiency in heat dissipation and therefore an increased operable current range of the electronic components mounted thereon, but also for the fan provided with the same to have a prolonged lifetime.
Still further, in the case that the protrusion of the circuit board is protruded outwardly with respect to the hub, since the heat-generating component provided on the protrusion is exposed to the airflow of the fan, the heat of the heat-generating component can be dispersed rapidly. Therefore, it is possible not only for the circuit board to enhance its efficiency in heat dissipation and therefore to increase the operable current range of the electronic components mounted thereon, but also for the fan provided with the circuit board to have a prolonged lifetime.
Other aspects and advantages of the invention will become apparent from the following detailed description in conjunction with the accompanying drawings, which illustrate by way of example the principles of the invention.
The hub 202 is coupled to the motor 120 so as to rotate synchronously with the motor 120 and drive the fan blades 204 to rotate accordingly. When the fan blades 204 rotate, an airflow flowing through the fan structure 200 is generated.
It should be understood that the various shapes and materials of the hub 202, motor, and the fan blades 204 can be chosen to meet the actual requirements. It will be obvious, however, to one skilled in the art, that the present invention may be practiced without some or all of these specific details. In other instances, the specific details have been omitted to avoid misinterpretation of the present invention.
The circuit board 100 comprises a circuit region 102 and a heat-dissipative film 106, wherein the heat-dissipative film 106 is located on the edge of the circuit board 100. The circuit region 102 includes circuits, semiconductor devices, integrated circuits and related components for driving the motor connected to the circuit board. Some of the components, such as the integrated circuit and semiconductor devices, can be grouped into a heat-generating component 104.
To be specific, the heat-dissipative film 106 is in contact with the heat-generating component 104 for dissipating the heat generated by the heat-generating component 104. Moreover, the heat of the heat-dissipative film 106 can be readily dispersed by means of airflow generated in the fan structure 200. The heat-dissipative film 106, for example, is a coating film made of heat-conducting material, wherein the heat-conducting material is selected from the group consisting of copper, aluminum, iron, and an alloy thereof.
Moreover, the heat-dissipative film 106 is provided to surround the circuit region 102. The heat-dissipative film 106 can also be located on any region of the circuit board 100 other than on the circuit region 102. Besides, the heat-dissipative film 106 may extend outside the circumference of the hub 202 as shown in
As shown in
Moreover, according to the structure of the circuit board 100, a heat sink (not shown) is further formed on the surface opposite to the surface of the circuit board 100 provided with the heat-dissipative film 106. The heat sink is connected to the heat-dissipative film 106 via a plurality of protruding portions of the heat sink, wherein the airflow passing through a plurality of through holes or the openings 108 thereof as shown in
Also, various shapes of the heat sink may be chosen to meet the actual requirements, such as a shape corresponding to the outline of the circuit board 100 or any other shapes. In addition, if another circuit region (not shown) is formed on the other surface of the circuit board, the heat sink can be located at any region of the circuit board 100 other than the circuit region.
Alternatively, as shown in
Moreover, as shown in
Alternatively, the heat-dissipative film 112 on the circuit board 500 is formed on the protrusion 110 as shown in
Furthermore, in order to enhance the efficiency in heat dissipation of the circuit board 500, a cutout 114 is formed through the protrusion 110 of a circuit board 600 as shown in
In conclusion, the circuit board of the invention is provided with a heat-dissipative film and/or a heat sink and thus the heat generated by the heat-generating component can be readily dispersed. Therefore, the efficiency in heat dissipation of the circuit board can be greatly enhanced.
Also, according to the fan structure of the invention, the heat-dissipative film may extend outside the circumference of the hub, thus the heat generated by the heat-generating component and dissipated to the heat-dissipative film and/or the heat sink can be readily dispersed by the airflow. Therefore, not only is the efficiency in heat dissipation and therefore the operable current range of the electronic components mounted thereon enhanced, but also the fan structure provided with the circuit board will have a prolonged lifetime.
Moreover, in the case where the protrusion of the circuit board extends outside the circumference of the hub, the heat generated by the operating fan can be readily dispersed because the heat-generating component is exposed to the airflow. Therefore, not only is the efficiency in heat dissipation and therefore the operable current range of the electronic components mounted thereon enhanced, but also the fan structure provided with the circuit board will have a prolonged lifetime.
Although the foregoing invention has been described in some detail for purposes of clarity and ease of understanding, it is apparent that certain changes and modifications may be practiced within the scope of the appended claims. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope and equivalents of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 92205657 | Apr 2003 | TW | national |
This application is a continuation application of U.S. Application Ser. No. 10/797,854, filed Mar. 10, 2004, the full disclosure of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| Parent | 10797854 | Mar 2004 | US |
| Child | 12712151 | US |
