Patent Application
20170181266
1. Field of Technology
The present principles relate to electronic devices with circuit boards having one or more components requiring heat dissipation. More particularly, it relates to a printed circuit board shield design for increasing component heat transfer/dissipation away from the components requiring the same.
2. Discussion of Related Art
Thermal management remains a significant challenge in electronic devices such as, for example, set top boxes and network gateways. With the introduction of more components having increased processing capabilities and increased functionalities, which tend to produce more heat, the need for an improved thermal management system exists.
An additional complication in the trend of electronic devices is the need to reduce the size of the device due to consumer preference. This trend for compactness also makes thermal management a challenge, because greater compactness with an increased number of internal components generally results in a higher concentration of heat.
Proper thermal contact between a thermal pad on a circuit board component and a heatsink improves heat dissipation from the circuit board. Additionally, heat spreaders (i.e., heatsinks) with associated shields (e.g., Radio Frequency or Ground shields) are often used to contain or prevent frequency interference generated by the electronic components on the circuit board, and can also operate to improve heat dissipation from one ore more electronic components. However, those of skill in the art will appreciate that existing structure and techniques for securing a shield with an associated heatsink against the thermal pad of a particular component results in an insufficient grounding of the heatsink within the electronic device.
Therefore, a need exists to provide sufficient grounding of the heatsink to the printed circuit board through the component shield without negatively impacting the required heat dissipation of one or more components contained within the confines of the shield.
Embodiments of the disclosure provide an electronic device having electronic device having a printed circuit board having one or more electronic components requiring heat dissipation. The electronic device includes a shield positioned on at least a part of the printed circuit board and having one or more heat transfer windows positioned over those electronic components requiring heat dissipation. A heatsink has one or more depressions configured to be positioned over and pass through the one or more heat transfer windows in the shield.
Embodiments of the disclosure are directed to an electronic device having a printed circuit board having one or more electronic components, and a shield configured to be positioned on at least a part of the printed circuit board. The shield includes at least one open heat transfer window positioned to be aligned with at least one electronic component requiring heat dissipation, and a ground connection associated with the at least one open heat transfer window. A heatsink has at least one depression configured to be aligned with the at least one open heat transfer window. In an embodiment, the ground connection can be formed by a plurality of ground fingers disposed at a selected spacing around the one or more heat transfer window that operates to block the applicable radiation wavelengths deemed to be detrimental, thus maintaining the shield's integrity for its intended purpose, while still providing the heat transfer window.
A more detailed understanding of the invention may be had from the following description, in conjunction with the accompanying drawings, wherein:
As illustrated in
Generally speaking, those of skill in the art will appreciate that the shield 16 is configured to shield part of the PCB components from the other components on the PCB for various reasons, but primarily to shield radio frequency interference from either radiating onto surrounding components from components contained within the shield, or generated by components outside the shield from affecting those components within the shield.
According to one implementation, the electronic device of the present principles would be a set top box generally provided to customers through respective content providers. In other implementations, the electronic device of the present principles can be a gateway device used to assist in the transmission of content to or from a customer or content source provider, respectively. Those of skill in the art will appreciate that other implementations of the present principles into many different types of electronic devices can be made without departing from the intended scope of the same.
Referring to
Referring to
Importantly, the ground fingers 120 around the periphery of the heat transfer window 108 physically and electronically couple the shield 106 to the heatsink 110. In this manner, the aforementioned problems associated with grounding of the heatsink 110 are eliminated and the heatsink is now sufficiently grounded to the PCB, via the ground fingers 120 of shield 106. In addition, once assembled, any potential losses in shielding created by the window 108 are eliminated by the fixation of the heatsink with depression 111 passing through the window 108. Those of skill in the art will appreciate that the metallic, electrically conductive body of the heatsink functionally closes the open heat transfer window 108. The ground fingers 120 are therefore spaced close enough together to prevent gaps larger than a selected maximum wavelength of a wavelength range which can be deemed to be detrimental, thereby effectively attenuating or blocking radiation wavelengths of radiation above that spacing size.
Those of skill in the art will appreciate that the physical form of ground fingers 120 may be different than that shown in the figures without departing from the intended scope of the present principles, provided such fingers are configured to consistently make a good physical and electrical connection with the corresponding heatsink/heat spreader. In one preferred implementation, the ground fingers 120 are spring biased upward such that the heatsink 110 will be forced downward against such spring bias when assembling the electronic device, thus assuring proper physical and electrical contact.
The foregoing illustrates some of the possibilities for practicing the present principles. Many other embodiments are possible within the scope and spirit of the present principles. It is, therefore, intended that the foregoing description be regarded as illustrative rather than limiting, and that the scope of the present principles is given by the appended claims together with their full range of equivalents.
