Patent Application
20090168344
The inventions generally relate to a thermal device with electrokinetic air flow.
Increasing levels of component power and power density from electronic devices such as a Central Processing Unit (CPU) and a GMCH (Graphics and Memory Controller Hub) are creating an increased demand for air flow in thermal management solutions. This results in high acoustic noise levels in computer platforms. A need for a more efficient cooling with low acoustic noise level signatures exists in order to expand the thermal dissipation performance envelope for, in particular, consumer electronics products such as set-top boxes and high definition (HD) televisions (TVs).
The inventions will be understood more fully from the detailed description given below and from the accompanying drawings of some embodiments of the inventions which, however, should not be taken to limit the inventions to the specific embodiments described, but are for explanation and understanding only.
Some embodiments of the inventions relate to a thermal device with electrokinetic air flow.
In some embodiments a thermal device such as a heat sink cools an electronic device. An electrokinetic airflow generating device uses a positively charged source and also uses at least a portion of the thermal device as a negatively charged or grounded probe to provide electrokinetically driven airflow.
Technology using the Electrokinetic effect has been used previously in commercial devices to ionize and purify air. It has also been used to cool electronic devices and systems. However, in some embodiments a heat sink is combined with an electrokinetically driven air flow generating device. According to some embodiments of combining a heat sink and electrokinetically driven air flow electronic device performance (for example, CPU performance) can be significantly improved while simultaneously reducing significantly the system ambient temperature.
In contrast to any previous work in this area where air generation was achieved by providing a set of positive and negative (and/or grounded) probes that are independent of cooling devices (such as heat sinks), in some embodiments, a metallic heat sink itself can be used as the negative/grounded plate.
In some embodiments, thermal devices (for example, heat sinks) are used as a negative and/or ground probe while positive probes can be made, for example, from metallic wires and/or point probes. Many different embodiments exist using either of these types of probes and using a combination of point and wire probes, and/or using many different types of thermal device (for example, heat sink) geometries. Some embodiments relate to Side-In-Side-Out (SISO) airflow configurations, and some embodiments relate to Top-In-Side-Out (TISO) airflow configurations. Some of these embodiments are illustrated and described herein.
It is noted that several different examples of probes and heat sinks and airflow configurations are illustrated and described herein for helping to explain embodiments of the invention.
However, there are many other embodiments of embedding FANLES technology into a thermal device (such as a heat sink) while using the thermal device as a negative/ground plate. Various modifications exist depending on the particular requirements and applications in a given scenario. Such variations may include a modification to the positive probes for higher performance as well as for better form-factor efficiencies, for example.
In some embodiments, hollow aluminum tubes of different diameters and different lengths may be used along with a bare-aluminum heat sink and/or an anodized heat sink. It has been empirically demonstrated that a substantial amount of airflow is generated, and the amount of airflow can be optimized by adjusting the size and length of the tube, the distance between the positive discharge and the heat sink, and the amount of electrical discharge.
In some embodiments, the flow velocity exiting the heat sink through a set of fins/fin-channel centered on a positive emitter is higher while adjacent channels have less (but still significant) airflow velocities. Therefore, in some embodiments, it is not necessary to have a point emitter per every fin-channel. In some embodiments, anodizing a heat sink does not have any impact on airflow velocity (for example, a center fin-channel velocity). In some embodiments, a heat sink is grounded via a mounting hole so the core metal has a path to ground.
In some embodiments, electrokinetic air propulsion is applied to cool electronics using a thermal device such as a heat sink as the ground probe. Previous work in electrokinetic air propulsion for electronics cooling focused on using a separate and independent Electrokinetic module to deliver air flow for the cooling. In contrast, in some embodiments, the separate ground/negative plates are replaced with a metallic heat sink to provide a smaller compact form-factor and a lower cost. In some embodiments, heat sinks of any integrated circuit such as a CPU and/or a chipset may be used. This is particularly compelling when used in applications where a low acoustic signature with high reliability is desirable, such as in typical consumer electronics devices such as set top boxes and digital TVs.
Although some embodiments have been described herein as being implemented using heat sinks, according to some embodiments these particular implementations may not be required and other thermal devices other than heat sinks may be used.
Although some embodiments have been described in reference to particular implementations, other implementations are possible according to some embodiments. Additionally, the arrangement and/or order of circuit elements or other features illustrated in the drawings and/or described herein need not be arranged in the particular way illustrated and described. Many other arrangements are possible according to some embodiments.
In each system shown in a figure, the elements in some cases may each have a same reference number or a different reference number to suggest that the elements represented could be different and/or similar. However, an element may be flexible enough to have different implementations and work with some or all of the systems shown or described herein. The various elements shown in the figures may be the same or different. Which one is referred to as a first element and which is called a second element is arbitrary.
In the description and claims, the terms “coupled” and “connected,” along with their derivatives, may be used. It should be understood that these terms are not intended as synonyms for each other. Rather, in particular embodiments, “connected” may be used to indicate that two or more elements are in direct physical or electrical contact with each other. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements are not in direct contact with each other, but yet still co-operate or interact with each other.
An algorithm is here, and generally, considered to be a self-consistent sequence of acts or operations leading to a desired result. These include physical manipulations of physical quantities. Usually, though not necessarily, these quantities take the form of electrical or magnetic signals capable of being stored, transferred, combined, compared, and otherwise manipulated. It has proven convenient at times, principally for reasons of common usage, to refer to these signals as bits, values, elements, symbols, characters, terms, numbers or the like. It should be understood, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities.
Some embodiments may be implemented in one or a combination of hardware, firmware, and software. Some embodiments may also be implemented as instructions stored on a machine-readable medium, which may be read and executed by a computing platform to perform the operations described herein. A machine-readable medium may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable medium may include read only memory (ROM); random access memory (RAM); magnetic disk storage media; optical storage media; flash memory devices; electrical, optical, acoustical or other form of propagated signals (e.g., carrier waves, infrared signals, digital signals, the interfaces that transmit and/or receive signals, etc.), and others.
An embodiment is an implementation or example of the inventions. Reference in the specification to “an embodiment,” “one embodiment,” “some embodiments,” or “other embodiments” means that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least some embodiments, but not necessarily all embodiments, of the inventions. The various appearances “an embodiment,” “one embodiment,” or “some embodiments” are not necessarily all referring to the same embodiments.
Not all components, features, structures, characteristics, etc. described and illustrated herein need be included in a particular embodiment or embodiments. If the specification states a component, feature, structure, or characteristic “may”, “might”, “can” or “could” be included, for example, that particular component, feature, structure, or characteristic is not required to be included. If the specification or claim refers to “a” or “an” element, that does not mean there is only one of the element. If the specification or claims refer to “an additional” element, that does not preclude there being more than one of the additional element.
Although flow diagrams and/or state diagrams may have been used herein to describe embodiments, the inventions are not limited to those diagrams or to corresponding descriptions herein. For example, flow need not move through each illustrated box or state or in exactly the same order as illustrated and described herein.
The inventions are not restricted to the particular details listed herein. Indeed, those skilled in the art having the benefit of this disclosure will appreciate that many other variations from the foregoing description and drawings may be made within the scope of the present inventions. Accordingly, it is the following claims including any amendments thereto that define the scope of the inventions.
