Abstract:
A method of cooling a multi-chip electronic module includes receiving in an inlet of the multi-chip module an amount of fluid, and passing the amount of fluid along a plurality of substantially parallel flow paths that extends between a heat spreader member and a printed circuit board supporting a plurality of electronic components. The plurality of electronic components is in thermal contact with an internal surface of the heat spreader member. A heat exchange is facilitated between the plurality of electronic components and the amount of fluid passing along the flow path.

Description:
CROSS-REFERENCES TO RELATED APPLICATION 
       [0001]    This application is a continuation of U.S. application Ser. No. 13/189,855 filed Jul. 25, 2011, the disclosure of which is incorporated by reference herein in its entirety. 
     
    
     BACKGROUND 
       [0002]    The present invention relates to the art of electronic systems and, and more specifically, to a heat spreader for electronic systems including multi-chip modules. 
         [0003]    Electronic devices are being designed to conform to smaller and smaller packages. Arranging an ever increasing number of electronic components into ever decreasing packages presents various challenges including heat dissipation. In addition to cooling the electronic components, heat must also be removed from power generation devices. At present, most electronic devices are coupled to heat sinks that facilitate heat dissipation. Power generation devices are generally coupled to fans. In addition to cooling the power generation device, often times the fan are arranged so as to draw air across the electronic components to further facilitate heat dissipation. 
       SUMMARY 
       [0004]    According to an embodiment of the present invention, a method of cooling a multi-chip electronic module includes receiving in an inlet of the multi-chip module an amount of fluid, and passing the amount of fluid along a plurality of substantially parallel flow paths that extends between a heat spreader member and a printed circuit board supporting a plurality of electronic components. The plurality of electronic components is in thermal contact with an internal surface of the heat spreader member. A heat exchange is facilitated between the plurality of electronic components and the amount of fluid passing along the flow path. 
         [0005]    Additional features and advantages are realized through the techniques of the present invention. Other embodiments and aspects of the invention are described in detail herein and are considered a part of the claimed invention. For a better understanding of the invention with the advantages and the features, refer to the description and to the drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS 
         [0006]    The subject matter which is regarded as the invention is particularly pointed out and distinctly claimed in the claims at the conclusion of the specification. The forgoing and other features, and advantages of the invention are apparent from the following detailed description taken in conjunction with the accompanying drawings in which: 
           [0007]      FIG. 1  is a perspective view of a multi-chip electronic module in accordance with an exemplary embodiment; 
           [0008]      FIG. 2  is a partial cross-sectional elevational side view of the multi-chip electronic module of  FIG. 1 ; 
           [0009]      FIG. 3  is a partial cross-sectional elevational end view of the multi-chip module of  FIG. 1 ; and 
           [0010]      FIG. 4  is a plan view of the multi-chip electronic module of  FIG. 1   
       
    
    
     DETAILED DESCRIPTION 
       [0011]    With reference now to  FIGS. 1-4 , a multi-chip electronic module in accordance with an exemplary embodiment is indicated generally at  2 . Multi-chip electronic module  2  includes a circuit board  4  having a first end portion  6  that extends to a second end portion  7 . Circuit board  4  also includes a first surface portion  9  and an opposing second surface portion  10 . A plurality of electronic components, one of which is indicated at  14 , are mounted to first surface portion  9  of circuit board  4 . The number, type, and particular arrangement of electronic components can vary. In the exemplary embodiment shown, electronic components  14  take the form of circuit chips. 
         [0012]    In accordance with the exemplary embodiment shown, multi-chip module  2  includes a heat spreader member  20  supported above first surface portion  9  of circuit board  4 . Heat spreader member  20  includes a body  24  having a first end  28  that extends to a second end  29 . In the exemplary embodiment shown, body  24  is formed from aluminum, however it should be understood that other heat conducting materials could also be employed. Body  24  also includes a first surface  34  and a second surface  35 . Although shown extending seamlessly between first and second ends  28  and  29 , it should be understood that body  24  could be formed in multiple pieces. Heat spreader member  20  and circuit board  4  cooperate for form an enclosed fluid duct  40 . Fluid duct  40  is defined by first surface portion  9  of circuit board  4  and second surface  35  of heat spreader member  20 . Fluid duct  40  includes a fluid inlet defined by first end portion  6  and first end  28  and a fluid outlet  44  defined by second end portion  7  and second end  29 . Multi-chip electronic module  2  is shown to include an outlet screen  47  arranged at fluid outlet  44 . It should be understood that multi-chip module  2  may include an inlet screen (not shown) at fluid inlet  42 . Outlet screen  47  and or an inlet screen (not shown) may be used individually or in combination. Fluid duct  40  includes a plurality of parallel flow paths  54 - 58  that extend between fluid inlet  42  and fluid outlet  44 . Multi-chip electronic module  2  is further shown to include a stiffener member  62  that extends over second surface portion  10  of circuit board  4  and a connector  67  arranged at fluid inlet  42 . As will be discussed more fully below, stiffener member  62  is mechanically linked to heat spreader member  20  to minimize strain in circuit board  4  and, by extension, on connections between circuit board  4  and electronic components  14 . 
         [0013]    In further accordance with an exemplary embodiment, heat spreader member  20  includes a plurality of cavities, one of which is indicated at  80 , formed in second surface  35 . Cavities  80  are configured to receive corresponding ones of electronic components  14 . As such, cavity size, depth, and geometry may vary depending on the particular electronic components  14  employed. Each cavity  80  includes at least one thermal interface surface  84  formed in second surface  35  that is in thermal contact with a surface (not separately labeled) of electronic component  14 . In the exemplary embodiment shown, thermal interface surface  84  includes a surface treatment  88  such as roughening, grooves, projections and the like. Surface treatment  88  limits any excursion of a thermal interface material (TIM)  93  arranged between electronic component  14  and thermal interface surface  84 . TIM  93  facilitates thermal transfer between electronic component  14  and heat spreader member  20 . 
         [0014]    Heat spreader member  20  is further shown to include a plurality of fin elements, one of which is indicated at  100  that extend from second surface  35 . Fin elements enhance heat exchange between fluid flowing through fluid duct  40  and heat spreader member  20 . The number, length, width, and depth of fin elements  100  can vary. In addition, heat spreader member  20  includes a plurality of mounting elements  110  that extend from second surface  35 . Mounting elements  110  provide a mechanical link between heat spreader member  20  and circuit board  4 . More specifically, when heat spreader member  20  is positioned upon circuit board  4 , mounting elements  110  abut first surface portion  9  so as to define a thermal interface gap (not seperately labeled). Each mounting element  110  includes a central passage  114  that is configured to receive a mechanical fastener  120 . In the exemplary embodiment shown, mechanical fastener  120  extends into and engages with stiffener member  62 . However, it should be understood, that mechanical fastener  120  could also extend through stiffener member  62  and be provided with, for example a nut. Alternatively, mechanical fastener  120  could terminate within circuit board  4 . 
         [0015]    At this point it should be understood that the exemplary embodiments provide a multi-chip electronic module having a heat spreader member that defines a fluid duct configured to receive a fluid, such as air, that is passed in a convective heat exchange relationship with electronic components mounted to a circuit board. The fluid can be supplied by a fan directly mounted to the multi-chip electronic module, or be linked to the fluid inlet via ducting. In addition to exchanging heat with the fluid, the electronic components exchange heat conductively with the heat spreader member in order to further lower localized temperatures. The combination of convective and conductive heat exchange enables the multi-chip module to support a wide array of electronic components including both power generating and power consuming devices. 
         [0016]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one more other features, integers, steps, operations, element components, and/or groups thereof. 
         [0017]    The description of the present invention has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the invention in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the invention. The embodiment was chosen and described in order to best explain the principles of the invention and the practical application, and to enable others of ordinary skill in the art to understand the invention for various embodiments with various modifications as are suited to the particular use contemplated 
         [0018]    While the preferred embodiment to the invention had been described, it will be understood that those skilled in the art, both now and in the future, may make various improvements and enhancements which fall within the scope of the claims which follow. These claims should be construed to maintain the proper protection for the invention first described.