1. Field of the Invention
The present invention relates to applications of modular computer cores. More particularly, the present invention relates to the use of a hybrid circuit including a high-power processor and a low-power processor to provide a selectable “thermal design power” (TDP) in a thermal module together with an air-flow design.
2. Discussion of the Related Art
In recent years, small and thin computing devices are highly favored. Some examples of small and thin computing devices include the iPad and the iPhone from Apple Computer, Inc., the “ultrabooks” notebook computers from Intel Corporation and its partners, and the ultra-thin “Android smartphones” from Google, Inc. and its partners. To support these “ultra” devices, microprocessor manufacturers have provided low-power microprocessors (e.g., the ARM microprocessors, or fan-less x86 microprocessors). These microprocessors—which dissipate less than 3 W TDP (i.e., 3 watts of “Thermal Design Power”)—are primarily targeted for basic applications. To execute more advanced applications, higher power microprocessors are needed. But microprocessors that have a TDP that is higher than 3 watts require a proper thermal module for heat dissipation. In addition, the size of a typical ultra-computing device (i.e., roughly, the size of a smartphone) makes it difficult to squeeze a proper thermal module into the limited space. Other constraints on such a device include: (i) the device as a whole has to be as light as possible; (ii) the form factor has to be handheld size; (iii) noise has to be kept to a minimum, so as to be non-intrusive on the user carrying it very closely to the body (e.g., in a shirt pocket); and (iv) the exterior case temperature has to be kept low enough to be handheld permissible. Therefore, a new thermal module that is able to dissipate heat of a high-power microprocessor within the limited space of an ultra-computing device is desired to support advanced applications.
Metal blocks have been used as heat sinks that are mounted on low-power fan-less microprocessors to dissipate heat. It is also common to use metal chassis or cases to serve as passive heat sinks for low-power microprocessors. However, to transfer heat away from a higher power microprocessor, a much larger and more complete thermal module is required. Such a thermal module may include a heat dissipation plate, a heat pipe, and a heat sink. Further, it is customary also to include an integrated fan to increase airflow over the heat sink to expel the heated air out of the chassis or case quickly.
Excluding the display and the touch panel, the body of a typical ultra-thin device is less than one centimeter thick. A bulky heat dissipation block does not fit in this thickness. In addition, it is impossible to put a conventional cooling fan within the confines of the smartphone-size computer. It is a challenge to computer supplies to find a design that cools down a smartphone size computer in which a high-power microprocessor is used. In an attempt to provide such a solution, some computer thermal management companies (e.g., SUNON in Taiwan) designed powerful “mighty mini-fans” that fit into the limited space. However, these new “mini” products do not generate enough airflow to cool a high-power microprocessor in an effective manner.