A retainer is usually implemented to facilitate close attachment of a heat sink onto an IC to provide efficient heat dispersion. This is desirable to keep the IC cool under normal conditions, particularly during high-speed operation. Operating temperatures above a predetermined threshold, for example, can result in logical and electrical malfunctions. Extended operation at high temperature, or operation at extreme temperatures, can cause permanent electrical or mechanical damage and/or failure of the IC.
As the name implies, in the past, heat sink retainers have been use merely to firmly attach the heat sink to the IC. In this manner, while they provide mechanical attachment, due to their limited surface area, they provide little to no additional cooling. Indeed, the retainers can actually reduce the surface area available for use on the heat sink, reducing the heat sink's capacity for heat rejection.
Examples of the present disclosure comprise systems and apparatus for retaining a heat dissipating/absorbing device (“heat sink”) on a heat source. In some examples, the heat sink can comprise a first side in contact with the heat source. The heat sink can also comprise a plurality of heat sink cooling fins disposed on the second side of the heat sink designed to dissipate the heat generated by the heat source. In some examples, the heat source can be an integrated circuit (IC) or other electronic or electromechanical device that generates heat in the normal course of operation.
The apparatus can comprise a retainer designed to detachably couple, or clip, the heat sink onto the IC (or other heat source). The retainer can include a plurality of retainer cooling fins designed to work in concert with the heat sink cooling fins to improve the performance of the heat sink/retainer system (“the system”). In some examples, the retainer cooling fins can be disposed in a geometrical pattern that is the same as, or similar to, the geometrical pattern of the heat sink cooling fins. In other examples, the retainer cooling fins can be sized and shaped to direct air around the frame of the retainer or through the heat sink, among other things.
The retainer cooling fins can be shaped to direct, improve, and/or smooth airflow over the system. In some examples, the retainer cooling fins can be substantially wedge-shaped—with the base wider than the tip—to smooth airflow over the frame of the retainer. In other examples, the retainer cooling fins can be substantially airfoil-shaped—such that one side of the retainer cooling fin is longer than the other—to smooth and direct airflow in a particular direction.
The retainer can include one or more alignment pins and or alignment slots to enable the retainer, heat dissipation device, and heat source to be aligned and detachably coupled. The retainer can also include one or more vertical projections, or walls, to further align and/or contain the heat dissipation device and heat source. In some examples, the retainer can also include one or more hold-downs to enable the retainer to exert downward pressure on the heat sink to maintain contact between the heat sink and heat source.
The related drawings in connection with the detailed description of this disclosure, which is to be made later, are described briefly as follows, in which:
Examples of the present disclosure can comprise a system for cooling a heat source, such as an IC. The system can include a retainer for mechanically attaching a heat absorbing/dissipating device (e.g., a heat sink) to a heat source (e.g., an IC). The retainer can include multiple arms and tabs for attachment of the heat sink to the IC. The retainer can also include a plurality of cooling fins to provide additional cooling to the IC and replace the cooling fins on the heat sink that are normally removed to provide attachment locations.
For ease of explanation, the apparatus and system are discussed below with reference to a heat sink and a retainer for use on an IC. One of skill in the art will recognize, however, that in addition to ICs, the system could also be used to cool other electronic, electromechanical, and mechanical heat sources. In addition, while described as a system for use with a finned heat sink, the system could also be used in conjunction with other devices such as, for example, CPU water coolers, radiators, and printed circuit boards.
As mentioned above, a problem with existing heat sink retainers is that they (1) do not provide any additional cooling capacity and (2) actually reduce the cooling capacity of a heat sink. The retainers do not provide any appreciable cooling capacity because they are generally flat metal plates concerned only with attaching the heat sink to the IC, for example. Thus, while they may have clips, alignment pins, arms, or other attachment means, they do not provide significant additional cooling. In addition, in order for the retainer to attach the heat sink to the IC, there are generally no fins on the heat sink in the one or more locations where the retainer interfaces with the heat sink. As a result, the heat sink has fewer fins than would be available otherwise, reducing its cooling capacity.
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The retainer 100 can comprise a substantially square or rectangular frame 112 sized and shaped to fit a particular heat sink 104. In some examples, the frame 112 can comprise one or more standardized shapes designed to fit standard heat sinks 104. In other examples, the frame 112 can be “custom,” or specific, to each type of heat sink 104. The frame 112 can comprise lateral rails 114 and longitudinal rails 116.
The heat sink 104 can include a plurality of heat sink cooling fins 110. The heat sink cooling fins 110 increase the surface area of the heat sink 104 significantly and enable the heat sink 104 to reject exponentially more heat. In the area of the heat sink 104 where it engages with the retainer 100, however, there are generally one or more rows 108 of heat sink cooling fins 110 missing. This obviously measurably reduces the cooling capacity of the heat sink 104.
Using a conventional, flat retainer, however, does nothing to remedy this loss of cooling capacity. Indeed a conventional retainer is doubly inefficient. In other words, the retainer itself provides little, or no, additional cooling because it simply comprises flat components. In addition, the heat sink 104 has fewer heat sink cooling fins 110 due to the attachment location of the retainer. In some examples, therefore, the retainer 100 disclosed herein can comprise one or more retainer cooling fins 118.
In some examples, as shown, only the lateral rails 114 can include retainer cooling fins 118. This may be useful to match the fin pattern 138 on the retainer 100 to the fin pattern 136 on the heat sink 104, for example, to improve airflow, direct airflow, or to improve the uniformity of airflow over the heat sink 104 and/or IC 106. This may be useful to prevent localized overheating of the heat sink 104 and/or the IC 106, to avoid turbulence, or to direct airflow over and around obstacles, among other things. In other examples, the fin pattern 138 on the retainer 100 can be the same as the fin pattern 136 on the heat sink 104 simply due to packaging, handling, or other requirements. In other examples, the fin patterns 136, 138 can be different to facilitate turbulent flow, for example, or to direct air in a particular direction.
In other examples, the longitudinal rails 116 can also include retainer cooling fins 118 in addition to, or instead of, the lateral rails 114. This may be useful to further increase the cooling capacity of the retainer 100, for example, by further increasing the surface area of the retainer 100. In some examples, this may enable the retainer 100/heat sink 104 system to meet certain cooling requirements for the IC 106. In some examples, space simply may not be at a premium, enabling extra retainer cooling fins 118 to be included on the frame 112 of the retainer 100. In still other examples, the retainer cooling fins 118 located on the longitudinal rails 116 can be disposed perpendicular to the heat sink cooling fins 110 on the lateral rails 114. This may be useful to contain or direct the airflow over the heat sink 104 and/or IC 106. In other words, the retainer cooling fins 118 located on the longitudinal rails 116 and the heat sink cooling fins 110 on the lateral rails 114 can act to “box in” the airflow over the heat sink 104 and IC 106 to improve the volume, velocity, or laminarity of the airflow, among other things.
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In some examples, the clip 120 can also comprise a tab 120b. The tab 120b can be sized and shaped to mechanically affix the heat sink 104 to the IC 106 (or other heat source). In some examples, one or more of the retainer 100, clip 120, vertical wall 120a, or tab 120b can comprise a relatively resilient material (e.g., plastic, spring steel, or aluminum) to enable the vertical wall 120a and/or tab 120b to provide some spring-back. In this method the retainer 100 can simply be placed over the heat sink 104 and IC 106, for example, and be “snapped” into place.
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The hold downs 130 can enable the retainer 100 to press the heat sink 104 firmly against the IC 106. By applying even pressure to the heat sink 104, the hold downs 130 can improve thermal conduction between the heat sink 104 and the IC 106 and reduce vibration, among other things. In some examples, the hold downs 130 can be sized and shaped to coincide with the columns 132 of heat sink cooling fins 110 on the heat sink 104. In this manner, the hold downs 130 can apply firm downward pressure to the base 134 of the heat sink 104 without damaging the heat sink cooling fins 110. In some examples, heat sink grease can be applied between the heat sink 104 and the IC 106 to further improve conduction.
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As used herein the terms cooling, cooling capacity, heat rejection, heat rejection capacity, heat dissipation, heat dissipation efficiency, and like terms are used interchangeably. These terms are used to denote the general ability of a heat sink and/or retainer to maintain the temperature of an IC by absorbing and/or dissipating heat to, for example, the ambient air or liquid coolant. In addition, while the heat sinks discussed herein are shown as standard, finned heat sinks for ICs, examples of the present disclosure could also be used with other types of heat dissipation devices.
While several possible examples are disclosed above, examples of the present disclosure are not so limited. For instance, while systems and methods for use with ICs have been disclosed, the systems and methods could also be used with other electronic, electrical, electromechanical, or mechanical systems, for example, without departing from the spirit of the disclosure. In addition, while generally referred to above as a retainer for a heat sink in a computer or electronics setting, the system can be used to retain many types of mechanisms to increase their heat rejection capacity. Such changes are intended to be embraced within the scope of this disclosure.
The specific configurations, choice of materials, and the size and shape of various elements can be varied according to particular design specifications or constraints requiring a device, system, or method constructed according to the principles of this disclosure. Such changes are intended to be embraced within the scope of this disclosure. The presently disclosed examples, therefore, are considered in all respects to be illustrative and not restrictive. The scope of the disclosure is indicated by the appended claims, rather than the foregoing description, and all changes that come within the meaning and range of equivalents thereof are intended to be embraced therein.