Abstract:
In some embodiments, piezoelectric air jet augmented cooling for electronic devices is presented. In this regard, an apparatus is introduced having a plurality of more than about one hundred lead-free piezoelectric layers and electrodes stacked on top of each other and formed around a central opening, and a diaphragm coupled to the piezoelectric layers and substantially covering the central opening to vibrate and blow air when an operating voltage is applied to the electrodes. Other embodiments are also disclosed and claimed.

Description:
FIELD OF THE INVENTION 
   Embodiments of the present invention generally relate to the field of electronic device cooling and, more particularly, to piezoelectric air jet augmented cooling for electronic devices. 
   BACKGROUND OF THE INVENTION 
   Many electronic devices, for example integrated circuit devices, in computing systems need an active or passive cooling solution to keep from overheating. Cooling solutions, especially for smaller computing systems, are generally constrained in terms of their size and the amount of noise they can produce. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements, and in which: 
       FIG. 1  is a graphical illustration of a cross-sectional view of an example piezoelectric air jet, in accordance with one example embodiment of the invention; 
       FIG. 2  is a graphical illustration of an overhead view of the piezoelectric air jet depicted in  FIG. 1 , in accordance with one example embodiment of the invention; 
       FIG. 3  is a graphical illustration of a cross-sectional view of an example implementation of piezoelectric air jet augmented cooling for electronic devices, in accordance with one example embodiment of the invention; and 
       FIG. 4  is a block diagram of an example electronic appliance suitable for implementing piezoelectric air jet augmented cooling, in accordance with one example embodiment of the invention. 
   

   DETAILED DESCRIPTION 
   In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that embodiments of the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention. 
   Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments. 
     FIG. 1  is a graphical illustration of a cross-sectional view of an example piezoelectric air jet, in accordance with one example embodiment of the invention. As shown, piezoelectric air jet  100  includes one or more of multi-layer piezoelectric stack  102 , central opening  104 , diaphragm  106 , piezoelectric layer  108 , electrode layer  110 , oscillation region  112 , travel distance  114 , and thickness  116 . In one embodiment, thickness  116  is less than about 1.5 millimeters. Piezoelectric air jet  100  may include additional elements, such as housing, clips, connectors, crystals, or other electronic or mechanical components, which aren&#39;t shown for ease of explanation. 
   Multi-layer piezoelectric stack  102  represents a stack or alternating piezoelectric layers  108  and electrode layers  110 . In one embodiment multi-layer piezoelectric stack  102  might comprise dozens of layers. In one embodiment multi-layer piezoelectric stack  102  might comprise of up to several hundred layers. Multi-layer piezoelectric stack  102  may include adhesive between layers and electrical connections between electrodes  110 , but these aren&#39;t shown for simplicity. Multi-layer piezoelectric stack  102  may be formed completely or partially around central opening  104 . 
   Piezoelectric layer  108  may comprise a lead-free piezoelectric material. In one embodiment, piezoelectric layer  108  comprises BaTiO 3 . Each piezoelectric layer  108  may be laminated using multilayer ceramic capacitor technology where each layer is between about 1-4 micrometers thick. In one embodiment, electrode  110  comprises nickel which is co-fired with piezoelectric layer  108  for reliable adhesion without the need for glue or epoxy. In one embodiment, electrode  110  is slightly longer than piezoelectric layer  108 . 
   Diaphragm  106  is coupled with multi-layer piezoelectric stack  102  and substantially covers central opening  104 . In one embodiment, diaphragm  106  is a flexible polymer made by injection molding a polymer into and/or around central opening  104 . When the multi-layer piezoelectric stack  102  is subject to some alternating current at an operating voltage, piezoelectric layer  108  will change its shape resulting in lateral vibration. In one embodiment, the operating voltage is less than about 5 volts. The vibrations in multi-layer piezoelectric stack  102  will cause diaphragm  106  to oscillate within oscillation region  112  with an elongation represented by travel distance  114 . In one embodiment, diaphragm  106  oscillates at a resonance frequency of the piezoelectric layers  108 . In one embodiment, the resonance frequency is greater than about 300 hertz. Other frequencies may be utilized to achieve a desirable combination of noise and air pressure. The oscillation of diaphragm  106  may produce airflow  118  into and then out of central opening  104 . In another embodiment, a housing (not shown) may direct airflow in and/or out from a single side of piezoelectric air jet  100 . In one embodiment, diaphragm  106  may have two opposing layers that bring air in between them and then force air out. Other embodiments of diaphragm  106  will occur to those skilled in the art and fall within the scope of the present invention. 
     FIG. 2  is a graphical illustration of an overhead view of the piezoelectric air jet depicted in  FIG. 1 , in accordance with one example embodiment of the invention. In accordance with one example embodiment, piezoelectric air jet  100  includes one or more of multi-layer piezoelectric stack  102  and diaphragm  106 . While shown as being circular in shape, piezoelectric air jet  100  may comprise any of a variety of shapes. In one embodiment, piezoelectric air jet  100  is oval in shape. Also, while shown as being continuous, multi-layer piezoelectric stack  102  and/or diaphragm  106  may be discontinuous or segmented. 
     FIG. 3  is a graphical illustration of a cross-sectional view of an example implementation of piezoelectric air jet augmented cooling for electronic devices, in accordance with one example embodiment of the invention. As shown, computing device  300  includes chassis  302 , printed circuit board  304 , integrated circuit devices  306 , memory module  308 , connector  310 , memory devices  312 , advanced memory buffer  314 , clips  316 , clips  318  and power source  320 , which provides power for the electric components of computing device  300  and may include a battery or power supply. Computing device  300  may include multiple piezoelectric air jets  100 , for example to blow air on integrated circuit devices  306  and to blow air on advanced memory buffer  314  of memory module  308 . 
   Chassis  302  may provide mechanical strength and stability to computing device  300  and to house the other components of computing device  300 . Printed circuit board  302  may include electronic components, wires, traces and connectors, which aren&#39;t all shown for ease of understanding. Integrated circuit devices  306  may include memory devices, controllers, processors and the like. In one embodiment, due to a lack of space between chassis  302  and integrated circuit devices  306 , piezoelectric air jet  100  is attached to chassis  302  via clips  318  and positioned adjacent to integrated circuit devices. Although shown as attached using clips  318 , other means of attachment are possible and would not be outside the scope of the present invention. 
   Computing device  300  may also include memory module  308 , which is coupled with printed circuit board  304  through connector  310 . Memory module  308  may comprise a fully buffered dual inline memory module (FB-DIMM), including memory devices  312  and advanced memory buffer  314 . Advanced memory buffer  314  may experience higher temperatures than memory devices  312  and may particularly benefit from the teaching of the present invention. In one embodiment, piezoelectric air jet  100  is coupled with memory module  308  through clips  316  and positioned adjacent to the advanced memory buffer  314  to provide a jet of air. In another embodiment, piezoelectric air jet  100  is positioned between adjacent memory modules  308 . 
     FIG. 4  is a block diagram of an example electronic appliance suitable for implementing piezoelectric air jet augmented cooling, in accordance with one example embodiment of the invention. Electronic appliance  400  is intended to represent any of a wide variety of traditional and non-traditional electronic appliances, laptops, cell phones, wireless communication subscriber units, personal digital assistants, or any electric appliance that would benefit from the teachings of the present invention. In accordance with the illustrated example embodiment, electronic appliance  400  may include one or more of processor(s)  402 , memory controller  404 , system memory  406 , input/output controller  408 , network controller  410 , and input/output device(s)  412  coupled as shown in  FIG. 4 . Electronic appliance  400  may include one or more piezoelectric air jet(s)  100  to blow air on a particular integrated circuit device(s) or to circulate air in general. 
   Processor(s)  402  may represent any of a wide variety of control logic including, but not limited to one or more of a microprocessor, a programmable logic device (PLD), programmable logic array (PLA), application specific integrated circuit (ASIC), a microcontroller, and the like, although the present invention is not limited in this respect. In one embodiment, processors(s)  402  are Intel® compatible processors. Processor(s)  402  may have an instruction set containing a plurality of machine level instructions that may be invoked, for example by an application or operating system. 
   Memory controller  404  may represent any type of chipset or control logic that interfaces system memory  406  with the other components of electronic appliance  400 . In one embodiment, the connection between processor(s)  402  and memory controller  404  may be a point-to-point serial link. In another embodiment, memory controller  404  may be referred to as a north bridge. 
   System memory  406  may represent any type of memory device(s) used to store data and instructions that may have been or will be used by processor(s)  402 . Typically, though the invention is not limited in this respect, system memory  406  will consist of dynamic random access memory (DRAM). In one embodiment, system memory  406  may consist of Rambus DRAM (RDRAM). In another embodiment, system memory  406  may consist of double data rate synchronous DRAM (DDRSDRAM). 
   Input/output (I/O) controller  408  may represent any type of chipset or control logic that interfaces I/O device(s)  412  with the other components of electronic appliance  400 . In one embodiment, I/O controller  408  may be referred to as a south bridge. In another embodiment, I/O controller  408  may comply with the Peripheral Component Interconnect (PCI) Express™ Base Specification, Revision 1.0a, PCI Special Interest Group, released Apr. 15, 2003. 
   Network controller  410  may represent any type of device that allows electronic appliance  400  to communicate with other electronic appliances or devices. In one embodiment, network controller  410  may comply with a The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11b standard (approved Sep. 16, 1999, supplement to ANSI/IEEE Std 802.11, 1999 Edition). In another embodiment, network controller  410  may be an Ethernet network interface card. 
   Input/output (I/O) device(s)  412  may represent any type of device, peripheral or component that provides input to or processes output from electronic appliance  400 . 
   In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form. 
   Many of the methods are described in their most basic form but operations can be added to or deleted from any of the methods and information can be added or subtracted from any of the described messages without departing from the basic scope of the present invention. Any number of variations of the inventive concept is anticipated within the scope and spirit of the present invention. In this regard, the particular illustrated example embodiments are not provided to limit the invention but merely to illustrate it. Thus, the scope of the present invention is not to be determined by the specific examples provided above but only by the plain language of the following claims.