Patent Publication Number: US-2011067910-A1

Title: Component securing system and associated method

Description:
BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to the field of computer systems, and, more particularly, to data compression in such. 
     2. Description of Background 
     A printed circuit board may be a platform for carrying electronic components as well as providing conductive pathways for such. Surface mounted technology (“SMT”) is a method of connecting an electronic component to a printed circuit board. Such a mounted electronic component may be referred to as a surface mounted component. 
     SUMMARY OF THE INVENTION 
     According to one embodiment of the invention, a system to secure a component to a circuit board may include a printed circuit board, a surface mounted component, and a lead carried by the surface mounted component. The system may also include a stencil adhered between at least one of the printed circuit board and the surface mounted component. The system may further include the lead being adjacent to the stencil. 
     The stencil may surround a portion of the lead. The system may further include a substance conductively joining the printed circuit board and the lead. The substance may comprise solder. 
     The stencil&#39;s coefficient of thermal expansion may be substantially similar to the printed circuit board&#39;s coefficient of thermal expansion. The stencil may be nonconductive and/or rigid. 
     The lead may comprise a plurality of leads in spaced relations. The surface mounted component may comprise a plurality of components assembled in a non-rigid assembly. 
     The adhesion may be provided by a resin. The resin&#39;s coefficient of thermal expansion may be substantially similar to the printed circuit board&#39;s and/or the stencil&#39;s coefficients of thermal expansion. 
     Another aspect of the invention is a method to secure a component to a circuit board. The method may include adhering a stencil to a printed circuit board. The method may further include positioning a surface mounted component adjacent the stencil and opposite the printed circuit, and where a lead carried by the surface mounted component is adjacent the printed circuit board and the stencil. The method may additionally include conductively joining the printed circuit board and the lead. The method may also include positioning at least a portion of the lead within the stencil. 
     In one embodiment, the system may include a printed circuit board, a surface mounted component, a lead carried by the surface mounted component, and a resin. The system may also include a stencil adhered by the resin between the printed circuit board and/or the surface mounted component. The system may further include the stencil being adjacent to the lead. The system may additionally include a substance conductively joining the printed circuit board and the lead. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic block diagram of a system to secure a component in accordance with the invention. 
         FIG. 2  is a schematic block diagram side view of  FIG. 1 . 
         FIG. 3  is a schematic block diagram of a surface mounted component in accordance with the invention. 
         FIG. 4  is a schematic block diagram illustrating the placement of the leads carried by the surface mounted component in accordance with the invention. 
         FIG. 5  is a schematic block diagram illustrating the positioning of the stencil and substance in accordance with the invention. 
         FIG. 6  illustrates some of the leads surrounded by the stencil in accordance with the invention. 
         FIG. 7  is a flowchart illustrating method aspects in accordance with the invention. 
         FIG. 8  is a flowchart illustrating method aspects according to the method of  FIG. 7 . 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Aspects of the invention are described below with reference to flowchart illustrations and/or block diagrams of methods, and apparatus (systems) according to embodiments of the invention. It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. 
     With reference now to  FIGS. 1-6 , a system  10  to secure a component to a circuit board or the like, is initially described. In one embodiment, the system  10  includes a printed circuit board  12 , a surface mounted component  14 , and a lead  16  carried by the surface mounted component. In another embodiment, the lead  16  conductively connects the surfaced mounted component  14  and the printed circuit board  12 . 
     In one embodiment, the system  10  includes a stencil  18  adhered between at least one of the printed circuit board  12  and the surface mounted component  14 . In one embodiment, the system  10  further includes the lead  16  being adjacent to the stencil  18 . In other words, at least one surface of the lead  16  is next to the stencil  18 . 
     In one embodiment, the stencil  18  surrounds a portion of the lead  16 . Stated another way, all sides of the portion of the lead  16  are next to the stencil  18 . In another embodiment, the system  10  includes a substance  20  conductively joining the printed circuit board  12  and the lead  16 . In one embodiment, the substance  20  comprises solder. 
     In one embodiment, the stencil&#39;s  18  coefficient of thermal expansion is substantially similar to the printed circuit board&#39;s  12  coefficient of thermal expansion. In another embodiment, the stencil  18  is nonconductive and/or rigid. 
     In one embodiment, the lead  16  comprises a plurality of leads in spaced relations. In another embodiment, the surface mounted component  14  comprises a plurality of components  22   a - 22   b  assembled in an assembly. In one embodiment, the assembly is non-rigid. 
     In one embodiment, the adhesion is provided by a resin  24 . In another embodiment, the resin&#39;s  24  coefficient of thermal expansion is substantially similar to the printed circuit board&#39;s  12  and/or the stencil&#39;s  18  coefficients of thermal expansion. 
     Another aspect of the invention is a method to secure a component to a circuit board, which is now described with reference to flowchart  26  of  FIG. 7 . The method begins at Block  28  and may include adhering a stencil to a printed circuit board at Block  30 . The method may also include positioning a surface mounted component adjacent the stencil and opposite the printed circuit, and where a lead carried by the surface mounted component is adjacent the printed circuit board and the stencil at Block  32 . The method may further include conductively joining the printed circuit board and the lead at Block  34 . The method ends at Block  36 . 
     In another method embodiment, which is now described with reference to flowchart  38  of  FIG. 8 , the method begins at Block  40 . The method may include the steps of  FIG. 7  at Blocks  30 - 34 . The method may additionally include positioning at least a portion of the lead within the stencil at Block  42 . The method ends at Block  44 . 
     In one embodiment, the system  10  includes a printed circuit board  12 , a surface mounted component  14 , a resin  24 , and a lead  16  carried by the surface mounted component. In another embodiment, the system  10  also include a stencil  18  adhered by the resin  24  between the printed circuit board  12  and/or the surface mounted component  14 . 
     In one embodiment, the system  10  further includes the stencil  18  being adjacent to the lead  16 . In another embodiment, the system  10  additionally includes a substance  20  conductively joining the printed circuit board  12  and the lead  16 . 
     In view of the foregoing, the system  10 , in one embodiment, may secure a component to a circuit board. 
     For example, surface mount, large area array connectors suffer from the fact that the solder joints have to bear all the mating mechanical loads. By design, solder joints should be expected to carry electrical current, not to provide mechanical strength to the connector structure. Known solutions provide mechanical relief to the connector solder joints by bolting the connector to the printed circuit board. But this solution adds unnecessary hardware to the connector, taking up real estate on the circuit board. 
     An additional solution is required that does not take up additional real estate on the circuit board, requiring no additional hardware and readily applicable to hardware already built. As a result, the system  10  proposed solution is to adhere a permanently bonded nonconductive stencil to the SMT array to improve axial loading. 
     For instance, when plugging a daughtercard connector, the surface mount solder joints may absorb the majority of the load, which may cause unacceptable stresses and fractures in the solder joints. In other words, such may result in soldered SMT pads providing most of the support load during plugging. 
     The system  10  addresses the foregoing problem by adding a stencil  18  bonded to the printed circuit board  12 . The stencil  18  reduces shear stress on the solder joints and SMT pads  16 , reduces solder shorts, improves rigidity of the printed circuit board  12 , improve alignment, reduce pad delamination, and improves electrical shielding, if designed to isolate signals. 
     In one embodiment, the load is distributed through the stencil  18  to reduce the stress on the SMT pad. In another embodiment, the stencil  18  is thicker than traditional stencils because solder shorts would not be a concern. 
     While the preferred embodiment to the invention has 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.