Abstract:
In some embodiments, an injection molded metal stiffener and integrated carrier for packaging applications is presented. In this regard, an apparatus is introduced comprising a microelectronic device package substrate, a microelectronic device coupled with a top surface of the package substrate, and an injection-molded, metal stiffener coupled with the package substrate, wherein the stiffener includes a central opening and at least partially surrounds the microelectronic device, and wherein the stiffener includes an overhang that extends along a side of the package substrate and incorporates a coupling feature. Other embodiments are also disclosed and claimed.

Description:
FIELD OF THE INVENTION 
       [0001]    Embodiments of the present invention generally relate to the field of integrated circuit package design and, more particularly, to an injection molded metal stiffener and integrated carrier for packaging applications. 
       BACKGROUND OF THE INVENTION 
       [0002]    As microelectronic components shrink in size, a trend has emerged to provide package substrates that may be characterized as thin core substrates (that is, substrates having a core with a thickness less than or equal to 400 microns and larger than zero), or no-core substrates (that is, substrates without cores). 
         [0003]    Disadvantageously, with a thin or no-core substrate, however, decrease in yield at first level chip attach due to warpage causing nonwets may occur during the package manufacturing process, such as, for example, during flip chip bonding where substrate flatness and rigidity are required. To address the above issue, the prior art sometimes provides substrates that may have a thickness of at least several tens of microns or more. However, the above measure disadvantageously detracts from further package size minimization. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]    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: 
           [0005]      FIG. 1  is a graphical illustration of a cross-sectional view of an example microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention; 
           [0006]      FIG. 2  is a graphical illustration of a cross-sectional view of an example microelectronic device package including an injection molded metal stiffener and integrated carrier, in accordance with one example embodiment of the invention; 
           [0007]      FIG. 3  is a graphical illustration of a cross-sectional view of another example microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention; 
           [0008]      FIG. 4  is a graphical illustration of a cross-sectional view of another example microelectronic device package including an injection molded metal stiffener and integrated carrier, in accordance with one example embodiment of the invention; and 
           [0009]      FIG. 5  is a block diagram of an example electronic appliance suitable for implementing a microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0010]    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, 
         [0011]    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. 
         [0012]      FIG. 1  is a graphical illustration of a cross-sectional view of an example microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention. As shown, integrated circuit package  100  includes one or more of microelectronic device  102 , package substrate  104 , substrate top surface  106 , injection molded metal stiffener  108 , stiffener overhang  110 , attachment feature  111 , stiffener rib  112 , conductive traces  114 , conductive contacts  116 , stiffener top surface  118 , substrate copper pad  120  and stiffener height  122 . 
         [0013]    Microelectronic device  102  is intended to represent any type of integrated circuit die. In one embodiment, microelectronic device  102  is a multi-core microprocessor. Microelectronic device  102  includes an active surface which contains the electrical connections that couple with conductive traces  114  at substrate top surface  106 . 
         [0014]    Package substrate  104  represents any type of microelectronic device package substrate. In one embodiment, package substrate  104  represents a multi-layer organic substrate. In one embodiment, conductive traces  114  conductively couple microelectronic device  102  on substrate top surface  106  through build up layers to conductive contacts  1   16 . Conductive contacts  116  couple with conductive traces  114  and allow integrated circuit package  100  to be electrically coupled, for example by a socket connection, to a circuit board. In one embodiment, conductive contacts  116  include solder bumps. In another embodiment, conductive contacts  116  include lands. 
         [0015]    Injection molded metal stiffener  108  is attached to package substrate  104  to provide stiffening, which one skilled in the art would recognize may be essential for very thin packages. The mold used to create injection molded metal stiffener  108  may include features such as stiffener overhang  110 , which may be designed to extend along one or more side(s) of package substrate  104 , attachment feature  111 , which may be designed to couple with a carrier, and/or stiffener rib  112 , which may be designed to extend vertically up from injection molded metal stiffener  108 . Injection molded metal stiffener  108  may include a central opening and at least partially surrounds microelectronic device  102 . Injection molded metal stiffener  108  may border all or fewer than all sides of microelectronic device  102 . 
         [0016]    In one embodiment, stiffener overhang  110  extends below conductive contacts  116  so that attachment feature  111  may couple with a backside of a carrier. While shown as an edge grip attachment feature that snaps into place, attachment feature  111  may be any feature (for example pins, tabs, or notches) to mechanically restrain integrated circuit package  100  to a carrier. 
         [0017]    In one embodiment, injection molded metal stiffener  108  is composed substantially of magnesium. In other embodiments, injection molded metal stiffener  108  may be composed of magnesium-zinc, magnesium-aluminum, or other magnesium or aluminum or zinc alloys. In one embodiment, the metal used to mold injection molded metal stiffener  108  is chosen for thixotropic properties, such that when heated near its melting point and shear forces are applied, the metal may have viscous or plastic-like flow properties. 
         [0018]    In one embodiment, stiffener top surface  118  is substantially flush with substrate top surface  106 , though in other embodiments, stiffener top surface  118  may be extend above or below substrate top surface  106 . Injection molded metal stiffener  108  may be coupled with package substrate  104  before or after or contemporaneous to microelectronic device  102  is coupled with package substrate  104 . Package substrate  104  may include copper pad  120  through which injection molded metal stiffener  108  is soldered to package substrate  104 . In another embodiment, a polymer adhesive is used to bond injection molded metal stiffener  108  with package substrate  104 . Injection molded metal stiffener  108  may have a stiffener height  122  of a little as about 12 mils. 
         [0019]      FIG. 2  is a graphical illustration of a cross-sectional view of an example microelectronic device package including an injection molded metal stiffener and integrated carrier, in accordance with one example embodiment of the invention. As shown, assembly  200  includes one or more of integrated circuit package  100  and carrier  202 . 
         [0020]    Carrier  202  may represent a circuit board, such as a motherboard, with openings to accept attachment features  111 . In one embodiment, carrier  202  represents a manufacturing tray. Attachment features  111  of integrated circuit package  100  may slide or snap into place under carrier  202  mechanically holding integrated circuit package  100  in place. In one embodiment integrated circuit package  100  is held in place so that conductive contacts  116  can be reflowed to pads on top of carrier  202 . 
         [0021]      FIG. 3  is a graphical illustration of a cross-sectional view of another example microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention. As shown, integrated circuit package  300  includes one or more of microelectronic device  302 , package substrate  304 , injection molded metal stiffener  306 , stiffener overhang  308 , attachment feature  309 , stiffener rib  310 , substrate top surface  312 , and stiffener height  3   14 . 
         [0022]    Package substrate  304  may represent a bump-less build up layer substrate. In one embodiment, microelectronic device  302  and injection molded metal stiffener  306  are placed on a holding plate while encapsulation material is disposed between them forming a bond. Substrate top surface  312  may then be formed under the device and stiffener combination, followed by subsequent substrate layers. Injection molded metal stiffener  306  may include a central opening and at least partially surrounds microelectronic device  302 . Injection molded metal stiffener  306  may be adjacent to all or fewer than all sides of microelectronic device  302 . 
         [0023]    In one embodiment, stiffener overhang  308  extends below integrated circuit package  300  so that attachment feature  309  may couple with a backside of a carrier. While shown as notched tab attachment feature that slides into place, attachment feature  309  may be any feature (for example pins, tabs, rivets or notches) to mechanically restrain integrated circuit package  300  to a carrier. 
         [0024]    While shown as including stiffener rib  310 , injection molded metal stiffener  308  may be formed without this feature. In one embodiment, stiffener height  314  is substantially equal to the height of microelectronic device  302 . 
         [0025]      FIG. 4  is a graphical illustration of a cross-sectional view of another example microelectronic device package including an injection molded metal stiffener and integrated carrier, in accordance with one example embodiment of the invention. As shown, assembly  400  includes one or more of integrated circuit package  300  and carrier  402 . 
         [0026]    Carrier  402  may represent a circuit board, such as a motherboard, with openings to accept attachment features  309 . In one embodiment, carrier  402  represents a manufacturing tray. Attachment features  309  of integrated circuit package  300  may slide or snap into place under carrier  402  mechanically holding integrated circuit package  300  in place. In one embodiment integrated circuit package  300  is held in place so that conductive contacts of integrated circuit package  300  can be reflowed to pads on top of carrier  402 . 
         [0027]      FIG. 5  is a block diagram of an example electronic appliance suitable for implementing a microelectronic device package including an injection molded metal stiffener with an attachment feature, in accordance with one example embodiment of the invention. Electronic appliance  500  is intended to represent any of a wide variety of traditional and non-traditional electronic appliances, laptops, desktops, cell phones, wireless communication subscriber units, wireless communication telephony infrastructure elements, personal digital assistants, set-top boxes, or any electric appliance that would benefit from the teachings of the present invention. In accordance with the illustrated example embodiment, electronic appliance  500  may include one or more of processor(s)  502 , memory controller  504 , system memory  506 , input/output controller  508 , network controller  510 , and input/output device(s)  512  coupled as shown in  FIG. 5 . Processor(s)  502 , or other integrated circuit components of electronic appliance  500 , may comprise a microelectronic device package including an injection molded metal stiffener with an attachment feature as described previously as an embodiment of the present invention. 
         [0028]    Processor(s)  502  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)  502  are Intel® compatible processors. Processor(s)  502  may have an instruction set containing a plurality of machine level instructions that may be invoked, for example by an application or operating system. 
         [0029]    Memory controller  504  may represent any type of chipset or control logic that interfaces system memory  506  with the other components of electronic appliance  500 . In one embodiment, the connection between processor(s)  502  and memory controller  504  may be a point-to-point serial link. In another embodiment, memory controller  504  may be referred to as a north bridge. 
         [0030]    System memory  506  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)  502 . Typically, though the invention is not limited in this respect, system memory  506  will consist of dynamic random access memory (DRAM). In one embodiment, system memory  506  may consist of Rambus DRAM (RDRAM). In another embodiment, system memory  506  may consist of double data rate synchronous DRAM (DDRSDRAM). 
         [0031]    Input/output (I/O) controller  508  may represent any type of chipset or control logic that interfaces I/O device(s)  512  with the other components of electronic appliance  500 . In one embodiment, I/O controller  508  may be referred to as a south bridge. In another embodiment, I/O controller  508  may comply with the Peripheral Component Interconnect (PCI) Express™ Base Specification, Revision 1.0a, PCI Special Interest Group, released Apr. 15, 2003. 
         [0032]    Network controller  510  may represent any type of device that allows electronic appliance  500  to communicate with other electronic appliances or devices. In one embodiment, network controller  510  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  510  may be an Ethernet network interface card. 
         [0033]    Input/output (I/O) device(s)  512  may represent any type of device, peripheral or component that provides input to or processes output from electronic appliance  500 . 
         [0034]    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. 
         [0035]    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.