Abstract:
A downset edge integrated heat spreader is disclosed. The downset edge can be formed to an industrially accepted flatness with a single stamping operation. The downset edge can provide a surface for fastening the downset edge integrated heat spreader to a mounting substrate. The downset edge can also provide a component recess for mounting a component near a processor, but on the mounting substrate. The downset edge can also provide a warp and bend resistant structure during ordinary field use.

Description:
[0001]     This application is a divisional of U.S. patent application Ser. No. 10/405,055, filed on Mar. 31, 2003, which is incorporated herein by reference. 
     
    
     TECHNICAL FIELD  
       [0002]     Disclosed embodiments relate to an integrated heat spreader with a downset edge. More particularly, disclosed embodiments relate to an integrated heat spreader with a minimum deviation from planarity. Disclosed embodiments also include a process of forming the integrated heat spreader by a single-stamping process.  
       BACKGROUND INFORMATION  
       [0003]     Description of Related Art  
         [0004]     An integrated circuit (IC) die is often fabricated into a microelectronic device such as a processor. The increasing power consumption of processors results in tighter thermal budgets for a thermal solution design when the processor is employed in the field. Accordingly, a thermal interface is often needed to allow the die to reject heat more efficiently.  
         [0005]     Various techniques have been employed to transfer heat away from a die. These techniques include passive and active configurations. One passive configuration involves a conductive material in thermal contact with the backside of a packaged die. This conductive material is often a slug, a heat spreader, or an integrated heat spreader (IHS).  
         [0006]     A heat spreader is employed to spread and dissipate the heat generated by a die, which minimizes concentrated high-heat locations within the die. A heat spreader is attached proximate the back side of a microelectronic die with a thermally conductive material, such as a thermal interface material (TIM). A TIM can include, for example, thermally conductive gels, thermal greases, or solders. Heat spreaders include materials such as aluminum, copper, copper alloy, or ceramic, among others.  
         [0007]     With conventional technology, a packaged microelectronic device includes a die which is bonded from the back side to an integrated heat spreader (IHS). An IHS adhesive layer acts as a TIM to bond the die to the IHS. The conventional IHS includes a lip portion that is formed by a bending process which gives rise to less than complete filling into the corner of the bend. Additionally to form the lip portion of the HIS from a rectangular blank, several stamping processes are required to achieve a sufficiently flat upper and lower surfaces to achieve quality bonds with other structures such as heat sinks and dies, respectively. These stamping processes result in a relatively low yield range in the production of heat spreaders, due, at least in part, to the processes used for forming heat spreaders. Additionally, the stamping processes result in a significant variation in flatness of the top surface of the IHS, as well as the bottom surface. The variation in flatness can detrimentally affect adhesion to either side of the IHS.  
         [0008]     The current IHS, typically manufactured from a high purity copper alloy, is difficult to form with existing stamping equipment limitations, especially with respect to maintaining high raw material yield metrics &amp; fully-filled corner geometries that are achieved with the stamping process. In order to completely fill the corner locations of the IHS, typical industry raw material yields range as low as 35%, yet utilize multi-stage manufacturing with high-tonnage machinery. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0009]     In order to understand the manner in which embodiments are obtained, a more particular description of various embodiments briefly described above will be rendered by reference to the appended drawings. Understanding that these drawings depict only typical embodiments that are not necessarily drawn to scale and are not therefore to be considered to be limiting of its scope, some embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:  
         [0010]      FIG. 1  is a cross section of a microelectronic package according to an embodiment;  
         [0011]      FIG. 2  is a cross section of a downset edge integrated heat spreader according to an embodiment;  
         [0012]      FIG. 3A  is a perspective view of a microelectronic package according to an embodiment;  
         [0013]      FIG. 3B  is a perspective view of a microelectronic package according to an embodiment;  
         [0014]      FIG. 4A  is a cross section of a microelectronic package according to an embodiment;  
         [0015]      FIG. 4B  is a cross section of a microelectronic package according to an embodiment;  
         [0016]      FIG. 5  is a plan view of the microelectronic packaged depicted in  FIG. 4A ;  
         [0017]      FIGS. 6A and 6B  are perspective views of microelectronic packages according to embodiments;  
         [0018]      FIG. 7  is a process flow diagram according to an embodiment; and  
         [0019]      FIG. 8  is a depiction of a computer system. 
     
    
     DETAILED DESCRIPTION  
       [0020]     The following description includes terms, such as upper, lower, first, second, etc. that are used for descriptive purposes only and are not to be construed as limiting. The embodiments of a device or article described herein can be manufactured, used, or shipped in a number of positions and orientations.  
         [0021]     Reference will now be made to the drawings wherein like structures will be provided with like reference designations. In order to show the structures of embodiments most clearly, the drawings included herein are diagrammatic representations of inventive articles. Thus, the actual appearance of the fabricated structures, for example in a photomicrograph, may appear different while still incorporating the essential structures of embodiments. Moreover, the drawings show only the structures necessary to understand the embodiments. Additional structures known in the art have not been included to maintain the clarity of the drawings.  
         [0022]      FIG. 1  is a cross section of a microelectronic package according to an embodiment.  FIG. 1  depicts a microelectronic package  100  including a die  110  connected to a downset edge integrated heat spreader (IHS)  112  and a mounting substrate  114 . An IHS adhesive layer  116  acts as a thermal interface material (TIM) to bond the die  110  to the downset edge IHS  112 . The die  110  is coupled to the mounting substrate  114  through a series of electrical bumps  118  that are mounted on a series of bond pads  120  that are disposed upon the mounting substrate  114 .  
         [0023]     The downset edge IHS  112  includes a heat spreader body  122  and downset edges  124  and  126 . The downset edges appear as feet  124 ,  126  portions of the downset edge IHS  112 . Because the microelectronic package  100  is depicted in orthogonal cross section, the downset edges  124  and  126  are depicted as two separate downset edges. The downset edge walls  125 ,  127  of the downset edges  124  and  126 , respectively, form a perimeter for the entire downset edge IHS  112 . In one embodiment, the perimeter, delineated at the downset edge walls  125  and  127 , concentrically surrounds the heat spreader body  122  as it also delineates the entire perimeter of the downset edge IHS  112 . The downset edges  124  and  126  are downset from the heat spreader body bottom surface  128  by a foot height  130 . The foot height  130  forms a container recess  132  between the one or more downset edges  124 ,  126  and the bottom surface  128  of the downset edge IHS  112 . The dimension of the container recess  132  is approximately as deep as the thickness of the die  110 , the IS adhesive layer  116 , the electrical bump  118 , and the bond pad  120 , if present.  
         [0024]     The die  110  includes an active surface  134  and a backside surface  136 . The adhesive layer  116  forms a bond line thickness (BLT)  138  between the backside surface  136  of the die  110  and the bottom surface  128  of the downset edge IHS  112 .  
         [0025]     In a die-referenced process of assembling the microelectronic package  100 , the BLT  138  must take into account any particulates in the adhesive layer  116 . In one embodiment, the adhesive layer  116  includes a polymer. In one embodiment, the adhesive layer  116  includes a polymer with heat transfer particulates disposed therein. In one embodiment, the adhesive layer  116  includes a solder. In one embodiment, the adhesive layer  116  includes a solder with heat transfer particulates disposed therein. In one embodiment, the adhesive layer  116  includes a polymer-solder hybrid (PSH). In one embodiment, the adhesive layer  116  includes a PSH with heat transfer particulates disposed therein. In one embodiment the heat transfer particulates include graphite flakes and/or filaments. In one embodiment the heat transfer particulates include diamond solids. In one embodiment the heat transfer particulates include metals with a higher coefficient of thermal conductivity than the bulk of the adhesive layer  116 .  
         [0026]     In one embodiment, the downset edge IHS  112  is attached to the mounting substrate  114  by an attachment material  140 , such as a polymer or the like or another conventional sealant. In one embodiment the attachment material  140  is applied to at least a portion of the downset edges  124  or  126 . Attachment of the downset edge IHS  112  to the mounting substrate  114  may be by any number of methods, including but not limited to pressing, application of epoxy, soldering, or any suitable method known in the art. Additionally, mechanical attachment devices, such as a fastener  142  may be used to attach the downset edge IHS  112  to the mounting substrate. In one embodiment, the fastener  142  is a screw. In one embodiment, the fastener  142  is a nut and bolt assembly. In one embodiment, the fastener  142  is a staple. In one embodiment, the fastener  142  is a rivet. In one embodiment, the fastener  142  is a snap. In one embodiment, the fastener  142  is a press-fit taper pin. In one embodiment, the fastener  142  is a press pin. In one embodiment, the fastener is a clip (see  FIGS. 5 and 6 ). By reading this disclosure and practicing the embodiments, it should be apparent that any one, or a combination of fasteners set forth herein, and their respective equivalents can be used if desired.  
         [0027]     In one embodiment when the downset edge IHS  112  is attached to the mounting substrate  114 , the downset edge walls  125 ,  127  form an intermittent lip around the die  110  (see  FIGS. 5A and 5B ). In one embodiment, this intermittent lip may eliminate or reduce the need for a vent hole such as vent hole  332  of  FIG. 3 , which serves the primary purpose of providing pressure relief inside the package. Additionally, one or more of the discontinuities in the non-contiguous lip of the downset edge IHS  112  may serve as attachment locations for secondary devices, as set forth in further detail.  
         [0028]     As will be discussed in this disclosure, a notch  148  appears in the downset edge IHS  112 . In one embodiment, the notch  148  represents a displacement of the downset edges  124  and  126  away from the heat spreader body  122 , due to a stamping process or other process as will be set forth in this disclosure. In one embodiment, the notch  148  represents slip-shear of the downset edges  124  and  126  away from the heat spreader body  122 . By a slip-shear action, corner structures as illustrated in  FIG. 1  are substantially as dense as any given portion of the downset edge IHS  112 . In one embodiment, however, the downset edge IHS  112  is formed by a process such as one of molten casting, injection molding, or dry casting such as a powdered metal composite which can be formed by pressing and/or sintering. In these embodiments, the notch  148  is part of a mold impression.  
         [0029]     In one embodiment, the top surface  144  of the downset edge IHS  112  is substantially planar. By “substantially planar” it is understood that a deviation from planarity is minimized. Planarity is defined as a measure of the difference between the highest and lowest vertical points found along the top surface  144 , divided by the length  146  of the heat spreader body  122 . In one embodiment, the deviation from planarity is in a range from about 0.1 percent to about 0.5 percent. In one embodiment the length  146  of the heat spreader body  122  is in a range from about 5 millimeter (mm) to about 75 mm. In one embodiment the length  146  of the heat spreader body  122  is in a range from about 10 mm to about 50 mm. In one embodiment the length  146  of the heat spreader body  122  is in a range from about 20 mm to about 40 mm. In one embodiment the length  146  of the heat spreader body  122  is about 27 mm. In one embodiment the length  146  of the heat spreader body  122  is about 38.5 mm. In one embodiment the length  146  of the heat spreader body  122  is about 45 mm.  
         [0030]     The downset edge IHS  112  as shown in  FIG. 1  can be formed by use of one or more cold forming processes, such as, for example, one or more stamping processes. A stamping process may use a slug of material and then stamp out features or dimensions from the slug of material. In one embodiment, a stamping process is used to stamp down one or more downset edges  124 ,  126  to provide the downset edge IHS  112  set forth in this disclosure. The stamping process is given as one non-limiting method for forming the downset edge IHS  112  as shown and described, but any suitable method for forming a downset edge IHS  112  can be employed.  
         [0031]     There are pluralities of methods which may be used to form a downset edge IHS as claimed and described. These methods include, for example, stamping, machining, progressive manufacturing, laser cutting, injection molding, powder metal casting and others. One such method of forming a downset edge IHS includes starting with a mass of material, or slug, and cutting or machining it to a set of dimensions. Thereafter, one or more stamping processes are employed to form the downset edges  124  and  126 . In one embodiment, the process includes a single stamping event. In one embodiment, the process includes a plurality of stamping events.  
         [0032]      FIG. 2  is a side elevation of a downset edge IHS  212  according to an embodiment. In this embodiment, the downset edge IHS  212  includes at least one of a lower cladding layer  211  and an upper cladding layer  213 . By “cladding layer”, it is understood that a layer has been formed upon a heat sink structure such as the IHS  212 . Forming of a “cladding layer” thereon can include at least one of such diverse processes as pressure cladding, electroplating, electroless plating, and other processes. In one embodiment, a rectangular blank of IHS-grade copper is drawn through a molten nickel or molten nickel alloy bath to form at least one of the lower cladding layer  211  and of the upper cladding layer  213 . Subsequently, the nickel or nickel alloy-clad rectangular blank is cut. Hence, substantially no nickel or nickel alloy is depicted on laterally exposed surfaces.  
         [0033]     After cladding the downset edge IHS  212 , a single stamping process is carried out to form the downset edges  224  and  226 . The downset edge IHS  212  depicted in  FIG. 2  is therefore represented in one embodiment to be a nickel or nickel alloy-clad IHS-grade copper material. In one embodiment, the downset edge IHS  212  is copper or a copper alloy. In one embodiment, the downset edge IHS  212  is aluminum or an aluminum alloy. In one embodiment, the downset edge IHS  212  includes a graphite material. In one embodiment, the downset edge IHS  212  includes carbon structures such as carbon fibers and/or carbon particulates. In one embodiment, the downset edge IHS  212  includes a high thermal conductivity material such as diamond. In one embodiment, the downset edge IHS  212  includes a high thermal conductivity material formed from a consolidated metal powder.  
         [0034]     Where the downset edge IHS  212  is clad, such as with at least one of the lower cladding layer  211  and the upper cladding layer  213 , the cladding material is selected to provide adequate adhesion to the IHS material under ordinary test and field usages. In one embodiment, the cladding material includes nickel or a nickel alloy. In one embodiment, the cladding material includes gold or a gold alloy. In one embodiment, the cladding material includes silver or a silver alloy. Other materials for the IHS and the cladding material can be selected according to specific applications.  
         [0035]      FIG. 3A  is a perspective elevation of a microelectronic package  300  according to an embodiment. The microelectronic package  300  includes a downset edge IHS  312  which is disposed upon a mounting substrate  314 . The downset edge IHS  312  includes a heat spreader body  322  and a downset edge  324 . The downset edge  324  includes the downset edge wall  325 , which in this embodiment essentially concentrically surrounds the heat spreader body  322  in a continuous manner. The top surface  344  is also referred to as a first surface  344 . The downset edge wall  325  defines a boundary of a downset edge surface  350 . The downset edge surface  350  is also referred to as a second surface  350 . In  FIG. 3A , the second surface  350  is disposed below the first surface  344  according to the orientation of the microelectronic package  300  as depicted. Because the downset edge wall  325  is substantially continuous around the heat spreader body  322 , a vent hole  332  is provided. In one embodiment, no topside vent hole required. This embodiment is set forth subsequent with respect to other embodiments.  
         [0036]      FIG. 3B  is a perspective elevation of a microelectronic package  301  according to an embodiment. The microelectronic package  301  includes a downset edge IHS  313  which is disposed upon a mounting substrate  314 . The downset edge IHS  313  includes a heat spreader body  321  and a downset edge  323 . The downset edge  324  includes the downset edge wall  325 , which in this embodiment essentially concentrically surrounds the heat spreader body  321  in a continuous manner. The top surface  344  is also referred to as a first surface  344 . The downset edge wall  325  defines a boundary of a downset edge surface  350 . The downset edge surface  350  is also referred to as a second surface  350 . In  FIG. 3B , the second surface  350  is disposed below the first surface  344  according to the orientation of the microelectronic package  301  as depicted. Because the downset edge wall  325  is substantially continuous around the heat spreader body  321 , a vent hole  332  is provided. A discussion of no topside vent hole required is set forth subsequent with respect to other embodiments. After review of the downset edge IHSs depicted in  FIGS. 3A and 3B , one can read this disclosure and understand that other shapes can be achieved.  
         [0037]     During ordinary usage of a die such as the die  110  depicted in  FIG. 1 , heat management requires resistance to warping and bending of the mounting substrate  114 . This resistance to warping and bending, however, is in some ways limited to the immediate footprint of the downset edge IHS.  
         [0038]      FIG. 4A  is a cross section of a microelectronic die package according to an embodiment.  FIG. 4A  depicts a microelectronic package  400  including a die  410 , connected to a downset edge IHS  412  and a mounting substrate  414 . Although no cladding layer is depicted in  FIG. 4A , it is understood that a cladding layer such as at least one of the lower  211  and the upper  213  cladding layers ( FIG. 2 ) can be employed in the embodiment depicted in  FIG. 4A . An IHS adhesive layer  416  acts as a TIM to bond the die  410  to the downset edge IHS  412 . The die  410  is coupled to the mounting substrate  414  through a series of electrical bumps  418  that are mounted on a series of bond pads  420  that are disposed upon the mounting substrate  414 .  
         [0039]     The downset edge IHS  414  includes a heat spreader body  422  and downset edges  424  and  426 . The downset edges appear as feet  424 ,  426  portions of the downset edge IHS  412 . Because the microelectronic package  400  is depicted in orthogonal cross section, the downset edges  424  and  426  are depicted as two separate downset edges. The downset edge walls  425 ,  427  of the downset edges  424  and  426 , respectively, form a perimeter. In one embodiment, the perimeter, delineated at the downset edge walls  425  and  427 , concentrically surrounds the heat spreader body  422  and it also delineates the entire perimeter of the downset edge IHS  412 .  
         [0040]     In this embodiment, a top surface  444  of the downset edge IHS  412  is set above a downset edge surface  450 . Further in this embodiment, the downset edge surface  450  extends substantially to the edge  413  of the mounting substrate  414 . Where the downset edge IHS  412  is substantially stiffer than the mounting substrate  414 , the portion of the downset edge IHS  412  that includes the downset edges  424  and  426 , provides substantial resistance to warping and bending of the microelectronic package  400  during ordinary field use. Further because most of the downset edges  424  and  426  are remote from the die  410  where heat is generated, thermal expansion is minimized at the downset edges  424  and  426 . This minimization of thermal expansions of the downset edges  424  and  426  also results in less warping and bending of the mounting substrate  414 .  
         [0041]     In one embodiment, the fastener  442  is a screw. In one embodiment, the fastener  442  is a nut and bolt assembly. In one embodiment, the fastener  442  is a staple. In one embodiment, the fastener  442  is a rivet. In one embodiment, the fastener  442  is a snap. In one embodiment, the fastener  442  is a press-fit taper pin. In one embodiment, the fastener  442  is a press pin. In one embodiment, the fastener is a clip (see  FIGS. 5A and 5B ). By reading this disclosure and practicing the embodiments, it should be apparent that any one, or a combination of fasteners set forth herein, and their respective equivalents can be used if desired.  
         [0042]     The downset edge IHS  412  also exhibits two metrics regarding the exposed amount of horizontal upper  444  and lower  450  surfaces. As an aspect ratio, the length  446  of the heat spreader body  422 , can be divided by the length  447  of the downset edge  424  or  426 . In one embodiment, the aspect ratio is in a range from about 100:1 to about 0.2:1. This aspect ratio range can also encompass the embodiments depicted in  FIGS. 1-6 .  
         [0043]      FIG. 4B  is a cross section of a microelectronic die package according to an embodiment.  FIG. 4B  depicts a microelectronic package  401  including a die  410 , connected to a downset edge IHS  411  and a mounting substrate  414 . Although no cladding layer is depicted in  FIG. 4B , it is understood that a cladding layer such as at least one of lower  211  and the upper  213  cladding layers ( FIG. 2 ) can be employed in the embodiment depicted in  FIG. 4B . An IHS adhesive layer  416  acts as a TIM to bond the die  410  to the downset edge IHS  411 . The die  410  is coupled to the mounting substrate  414  through a series of electrical bumps  418  that are mounted on a series of bond pads  420  that are disposed upon the mounting substrate  414 .  
         [0044]     The downset edge IHS  414  includes a heat spreader body  422  and downset edges  424  and  426 . The downset edges appear as feet  424 ,  426  portions of the downset edge IHS  411 . Because the microelectronic package  400  is depicted in orthogonal cross section, the downset edges  424  and  426  are depicted as two separate downset edges. The downset edge walls  425 ,  427  of the downset edges  424  and  426 , respectively, form a perimeter. In one embodiment, the perimeter, delineated at the downset edge walls  425  and  427 , concentrically surrounds the heat spreader body  422  and it also delineates the entire perimeter of the downset edge IHS  412 .  
         [0045]     In one embodiment, the downset edge IHS  411  is attached to the mounting substrate  414  by an attachment material  441 , such as a polymer or other sealant. In one embodiment the attachment material  441  is applied to at least a portion of the downset edges  424  or  426 .  
         [0046]     In one embodiment, the attachment material  441  fills a recess in the downset edges  424  and  426 . In one embodiment, the attachment material  441  overflows onto the downset edge surface  450 . In one embodiment the recess has substantially tapered sidewalls, which form a locking structure when filled with the attachment material. In one embodiment the recess has substantially vertical sidewalls (not pictured).  
         [0047]     Attachment of the downset edge IHS  411  to the mounting substrate  414  may be by any number of methods, including but not limited to pressing, application of epoxy, soldering, or any suitable method known in the art.  
         [0048]     Additionally, mechanical attachment devices, such as a fasteners  443  may be used to attach the downset edge IHS  411  to the mounting substrate. In one embodiment, the fastener  443  is a screw. In one embodiment, the fastener  443  is a nut and bolt assembly. In one embodiment, the fastener  443  is a staple. In one embodiment, the fastener  443  is a rivet. In one embodiment, the fastener  443  is a snap. In one embodiment, the fastener  443  is a press-fit taper pin. In one embodiment, the fastener  443  is a press pin. In one embodiment, the fastener is a clip (see  FIGS. 5A and 5B ). By reading this disclosure and practicing the embodiments, it should be apparent that any one, or a combination of fasteners set forth herein, and their respective equivalents can be used if desired.  
         [0049]      FIG. 4B  also illustrates the presence of a heat slug  423  that is thermally coupled to the die  410  through a second TIM (TIM  2 )  415 . In one embodiment, the TIM  2   415 , along with the fasteners  443  minimizes what is often referred to as “tilt” in orientation of the heat slug  423  with respect to the IHS  413 . It is also noted that the heat slug  423  can be any thermally enabling solution as is known in the art, including but not limited to a finned heat sink, a heat pipe, and others.  
         [0050]      FIG. 5  is a plan view of the microelectronic package depicted in  FIG. 4 . The cross section of  FIG. 4A  is taken from  FIG. 5 , along the line  4 - 4 .  FIG. 5  includes a die  510 , depicted in phantom lines, disposed upon a mounting substrate  514 , and covered by a downset edge IHS  512  which includes an intermittent lip  525  which can be substantially concentric to the perimeter of the die  510 . In one embodiment, this intermittent lip  525  may eliminate or reduce the need for a vent hole such as vent hole  332  of  FIG. 3 , which, as stated previously, serves the primary purpose of providing pressure relief inside the package. In one embodiment, the intermittent lip  525  delineates the downset edge wall, also referred to in part as item  525 . The perimeter, however, is not limited to the downset edge wall  525 . Where a break in the downset edge wall  525  occurs, the perimeter deviates from a uniform distance from the geometric center of the heat spreader body  522 .  
         [0051]     Referring again to  FIG. 4A , the downset edge IHS  412  includes a downset region that includes an inner wall  452  and an outer wall  454 . In  FIG. 5 , the downset region includes an inner wall  552 , depicted in phantom lines, and an outer wall  554 . In one embodiment, a channel  556  communicates between the inner wall  552  and the outer wall  554 . Further in one embodiment, a channel recess  528  breaks the perimeter of the downset edge wall  525 , and exposes the mounting substrate  514  in the region of the channel  556 . In one embodiment, the channel recess  528  communicates through the downset edge  525 .  
         [0052]     Other component recesses  560 ,  562 , and  564  are depicted in arbitrary numbers and locations along the downset edge IHS  512 . In one embodiment, at least one of the component recesses  560 ,  562 , and  564  communicates through the downset edge  524 . By the occurrence of at least one of the channel recess  528  and component recesses  560  and  562  the intermittent lip  525  is present in the downset edge IHS  512  because each breaks the perimeter of the downset edge wall  525 . By the occurrence of the component recess  564 , the mounting substrate  514  is exposed, but the downset edge wall  525  is continuous in the region of the component recess  564  and the perimeter of the downset edge wall  525  is not broken at this location. In one embodiment, the presence of a recess such as one of the recesses  528 ,  560 ,  562 , and  564  allows for articles such as electronic components and/or leads to be mounted upon the mounting substrate  514 . In one embodiment, a decoupling capacitor (not pictured) is disposed in a recess upon the mounting substrate  514 . Other components known in the art can be disposed in a recess as described and claimed.  
         [0053]     Corresponding to the respective recesses  560 ,  562 , and  564 , clips  561 ,  563 , and  565  are depicted as being mounted upon the mounting substrate  514  at a sub-lower level, and simultaneously mounted upon the lower level  550  which is the downset edge  424 ,  426  (see  FIG. 4 ) of the downset edge IHS  512 . The clips  561 ,  563 , and  565  are depicted as utilitarian and generic. The clips  561 ,  563 , and  565  or at least one of them, however, can be customized to meet a given application. The clips  561 ,  563 , and  565  are depicted in addition to the fasteners  442 .  
         [0054]      FIG. 6A  is a perspective view of a microelectronic package according to an embodiment. The microelectronic package  600  includes a die (not shown) which is enclosed within a downset edge IHS  612 . The die and the downset edge IHS  612  are disposed upon a mounting substrate  614 . The upper surface  644  of the downset edge IHS  612  includes the heat spreader body  622  and a vent hole  632 . According to embodiments set forth herein, the downset edge  624  includes a downset edge wall  625 , which can surround and/or be substantially concentric to the heat spreader body  622 . The downset edge IHS  612  includes a notch  648  which is formed during manufacture of the downset edge IHS  612  according to embodiments set forth in this disclosure. A clip  659  is disposed upon the lower surface  650  of the downset edge IHS  612 , and also upon the sub-lower surface which is the surface of the mounting substrate  614 .  
         [0055]     In one embodiment, a clip  659  is fixed into position during pick-and-place fabrication of the microelectronic package  600 . In one embodiment, the clip  659  is fixed into position by a snap according to conventional technique. In one embodiment, a fastener is used such as the fasteners  542  depicted in  FIG. 5A .  
         [0056]      FIG. 6B  is a perspective view of a microelectronic package according to an alternative embodiment. The microelectronic package  601  includes a die (not shown) which is enclosed within a downset edge IHS  613 . The die and the downset edge IHS  613  are disposed upon a mounting substrate  614 . The upper surface  644  of the downset edge IHS  613  includes the heat spreader body  622  and a vent hole  632 . According to embodiments set forth herein, the downset edge  623  includes a downset edge wall  627  which surrounds and is substantially asymmetrical with respect to the heat spreader body  622 . A clip  659  is disposed upon the lower surface  651  of the downset edge IHS  613 , and also upon the sub-lower surface which is the surface of the mounting substrate  614 . In one embodiment, a fastener is used such as the fasteners  542  depicted in  FIG. 5A .  
         [0057]     It can now be appreciated that, although only one part of the downset edge  623  is depicted as substantially asymmetrical with respect to the heat spreader body  622 , more than one part of the downset edge  623  can be substantially asymmetrical. Further with respect to the channel and component recesses depicted in  FIG. 5 , such channel and/or component recesses, or one of them, or at least one of each of them, can be placed into the downset edge IHS  613  according to a specific application. In  FIG. 6B , a component recess  664  is depicted by way of non-limiting example. It can also be appreciated that a channel such as the channel  556  in  FIG. 5  can also be placed into a downset edge IHS such as the downset edge IHS  601  depicted in  FIG. 6B . By such placement, the vent hole  632  can be omitted.  
         [0058]      FIG. 7  is a process flow diagram according to an embodiment. The fabrication of a microelectronic package includes the formation of the downset edge IHS according to embodiments set forth in this disclosure. The process  700  includes embodiments which relate to the formation of a downset edge IHS.  
         [0059]     At  710 , a downset edge IHS is formed. At  712 , the downset edge IHS is formed by single-stamping a metal blank according any of the various embodiments set forth in this disclosure. At  714 , the downset edge IHS is formed by multiple-stamping a metal blank according any of the various embodiments set forth in this disclosure. At  716 , the downset edge IHS is formed by casting a metal blank according any of the various embodiments set forth in this disclosure. At  718 , the downset edge IHS is formed by injection molding a metal blank according any of the various embodiments set forth in this disclosure. At  720 , the downset edge IHS is formed by any other conventional forming technique according any of the various embodiments set forth in this disclosure. It can be appreciated that cladding the metal blank can precede, follow, or coincide with formation of the downset edge IHS  710 . At  711 , one process embodiment is completed.  
         [0060]     At  730 , a die is placed upon a mounting substrate. At  731 , one method embodiment is completed.  
         [0061]     At  740 , a downset edge IHS is placed over the die, and also upon the mounting substrate. At  741 , one method embodiment is completed.  
         [0062]     The several embodiments set forth in this disclosure are described primarily in the context of utilization with an integrated circuit flip-chip configuration, packaged with a substrate and heat spreader as shown in the accompanying figures. Other embodiments, however, can be employed that are not limited to just this particular configuration, and the claimed subject matter is applicable to other types of microelectronic packages. For example, microelectronic packages in accordance with the claimed subject matter may include packages with varying form factors, such as, for example, pin grid array, ball grid array, ball grid array with pinned interposers and wire bonding.  
         [0063]      FIG. 8  is a depiction of a computing system. One or more of the foregoing embodiments of a microelectronic package may be utilized in a computing system, such as a computing system  800  of  FIG. 8 . The computing system  800  includes at least one processor (not pictured) under a downset edge IHS  810 , a data storage system  812 , at least one input device such as keyboard  814 , and at least one output device such as monitor  816 , for example. The computing system  800  includes a processor that processes data signals, and may comprise, for example, a PENTIUM®III or PENTIUM® 4 microprocessor, available from Intel Corporation. In addition to the keyboard  814 , the computing system  800  can include another user input device such as a mouse  818 , for example. The computing system  800  may utilize one or more microelectronic packages such as described in one or more of the foregoing embodiments. For purposes of this application, a computing system  800  embodying components in accordance with the claimed subject matter may include any system that utilizes a microelectronic package, which may include, for example, a data storage device such as dynamic random access memory, polymer memory, flash memory, and phase-change memory. The microelectronic package can also include a die which contains a digital signal processor (DSP), a micro controller, an application specific integrated circuit (ASIC), or a microprocessor. It can now be appreciated that embodiments set forth in this disclosure can be applied to devices and apparatuses other than a traditional computer. For example, a die can be packaged with an embodiment of the downset edge IHS and placed in a portable device such as a wireless communicator or a hand-held device such as a personal data assistant and the like. Another example is a die which can be packaged with an embodiment of the downset edge IHS and placed in a vehicle such as an automobile, a locomotive, a watercraft, an aircraft, or a spacecraft.  
         [0064]     It is emphasized that the Abstract is provided to comply with 37 C.F.R. §1.72(b) requiring an Abstract that will allow the reader to quickly ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.  
         [0065]     In the foregoing Detailed Description, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate preferred embodiment.  
         [0066]     It will be readily understood to those skilled in the art that various other changes in the details, material, and arrangements of the parts and method stages which have been described and illustrated in order to explain the nature of this invention may be made without departing from the principles and scope of the invention as expressed in the subjoined claims.