Abstract:
In some embodiments, flexible joint methodology to attach a die on an organic substrate is presented. In this regard, an integrated circuit chip package substrate is introduced having an organic substrate, an interposer coupled with a surface of the organic substrate, the interposer having cavities to accept bumps of a die, and a flexible tape layer coupled with a surface of the interposer, the flexible tape layer to couple with bumps of the die. 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 packages, and, more particularly to flexible joint methodology to attach a die on an organic substrate. 
       BACKGROUND OF THE INVENTION 
       [0002]    The demand for enhanced performance and body size reduction of integrated circuit components continues to increase design and fabrication complexity due to the higher bandwidth requirements needed to enable higher clock frequencies. The substrates designed for these components will need to be manufactured with even smaller feature sizes to enable optimization of bandwidth. These smaller feature sizes are likely to lead to more occurrences of issues with conventional solder joints such as lagoon tail, miss-contact by small bumps, shorts to neighboring bumps, and voids in bumps. 
     
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0003]    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: 
           [0004]      FIG. 1  is a graphical illustration of an overhead view of a flexible tape with contact points, in accordance with one example embodiment of the invention; 
           [0005]      FIG. 2  is a graphical illustration of a cross-sectional view of an integrated circuit package with a flexible joint, in accordance with one example embodiment of the invention; 
           [0006]      FIG. 3  is a graphical illustration of a cross-sectional view of an integrated circuit package with a flexible joint, in accordance with one example embodiment of the invention; and 
           [0007]      FIG. 4  is a block diagram of an example electronic appliance suitable for implementing an integrated circuit package with a flexible joint, in accordance with one example embodiment of the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0008]    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. 
         [0009]    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. 
         [0010]      FIG. 1  is a graphical illustration of an overhead view of a flexible tape with contact points, in accordance with one example embodiment of the invention. In accordance with the illustrated example embodiment, flexible tape  100  includes one or more of contact point  102 , plated area  104 , via holes  106 , and cross cut slits  108 . 
         [0011]    Flexible tape  100  represents a film or reeled tape comprising flexible dielectric material that has been processed to include contact points, such as contact point  102 . In one embodiment, flexible tape  100  comprises polyimide tape with a thickness of 25 um, though other thicknesses may be selected by restitution (contact strength between a die bump and polyimide tape). In another embodiment, flexible tape  100  has a modulus of adhesion to maintain contact with bumps of an integrated circuit die. Flexible tape  100  may be processed as a reel and then cut into individual units for use with individual die or multiple dies. 
         [0012]    Contact point  102  represents one of a plurality of contact points designed to couple with bumps of a die. Contact point  104  includes a plated area  104 , via holes  106 , and cross cut slits  108 . 
         [0013]    Plated area  104  provides electrical conductivity from the bump of the die to via holes  106 . In one embodiment, plating area  104  comprises copper plating as the major conductive material and gold/nickel plating as a surface finish. 
         [0014]    Via holes  106  provide electrical coupling from plated area  104  to the substrate below through the interposer, as described in greater detail in reference to  FIGS. 2 &amp; 3 . While four via holes  106  are shown in  FIG. 1 , any number and any shape of via holes may be utilized so as provide adequate electrical conductivity. In one embodiment, via holes  106  are filled with gold or a gold alloy. In another embodiment, via holes  106  are filled with nickel or a nickel alloy. 
         [0015]    Cross cut slits  108  represent a pattern cut through flexible tape  100  to create flaps that can move down when a die bump is placed from above. As shown, cross cut slits  108  are x-shaped creating four flaps, however other shaped cross cut patterns may be utilized to create two or more flaps. In one embodiment, cross cut slits  108  are created by mechanical punching. In another embodiment, cross cut slits  108  are created by laser ablation. 
         [0016]      FIG. 2  is a graphical illustration of a cross-sectional view of an integrated circuit package with a flexible joint, in accordance with one example embodiment of the invention. As shown, integrated circuit package  200  includes die  202 , die bump  204 , flexible tape  206 , cavity  207 , interposer  208 , via  209 , underfill  210 , substrate bump  212 , substrate  214 , thermal interface material (TIM)  216 , integrated heat spreader (IHS)  218 , and capacitor  220 . 
         [0017]    Die  202  represents any type of integrated circuit, including, but not limited to, a microprocessor, a controller, a communications processor, or a graphics processor. As part of a manufacturing process die  202  may have die bump  204  among a plurality of solder bumps formed on one side. 
         [0018]    In one embodiment, flexible tape  206 , including contacts points such as contact point  102 , is aligned with and attached to interposer  208 , before die  202  is coupled to flexible tape  206 . In one embodiment, a gold surface of flexible tape  206 , for example via holes  106 , bond with a gold surface of interposer  208 . 
         [0019]    Interposer  208  may be ceramic or another dielectric material which provides mechanical support between die  202  and substrate  214 . Interposer  208  includes cavities, such as cavity  207  that can at least partially receive die bump  204  and flaps of flexible tape  206 . Cavity  207  is plated with a conductive metal, such as gold or nickel or copper or silver or tungsten, to electrically couple die bump  204  to substrate  214 . In one embodiment, interposer  208  also includes via  209 , which is filled with a conductive metal or alloy to electrically couple with substrate  214 . 
         [0020]    In one embodiment, substrate bump  212  is formed on via  209  of interposer  208 , and interposer  208  is coupled with substrate  214  through conventional soldering and underfill  210 . In another embodiment, substrate bump  212  is formed on substrate  214  and is soldered to via  209 . 
         [0021]    In one embodiment, die  202  is positioned and pressed down such that bump  204  is aligned of a contact point of flexible tape  206 , which is aligned with cavity  207 , forming a flexible, non-soldered, joint. Thereafter, thermal interface material  216  may be applied to a surface of die  202  to adhere with integrated heat spreader  218 . 
         [0022]    While shown in a package, the flexible joint shown in  FIG. 2  may be implemented in varying levels of completeness and complexity. For example, interposer  208  may be formed in an organic layer of substrate  214 . 
         [0023]      FIG. 3  is a graphical illustration of a cross-sectional view of an integrated circuit package with a flexible joint, in accordance with one example embodiment of the invention. As shown, integrated circuit package  300  includes die  302 , die bump  304 , flexible tape layers  306 , interposer  308 , cavity  309 , substrate bump  310 , substrate  312 , TIM  314 , IHS  316 , and capacitor  320 . 
         [0024]    In this embodiment, two flexible tape layers  306  are bonded on separate surfaces of interposer  308 , one to couple with die bump  304  and the other to couple with substrate bump  310 . In this embodiment, cavity  309  of interposer  308  extends to both flexible tape layers  306 , flaps of which extend into cavity  309 . 
         [0025]      FIG. 4  is a block diagram of an example electronic appliance suitable for implementing an integrated circuit package with a flexible joint, 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, 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  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. 5 . Processor(s)  402 , or other integrated circuit components of electronic appliance  400 , may be housed in a package including a flexible joint described previously as an embodiment of the present invention. 
         [0026]    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. 
         [0027]    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 referred to as a front-side bus. In another embodiment, memory controller  404  may be referred to as a north bridge. 
         [0028]    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). 
         [0029]    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. 
         [0030]    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. 
         [0031]    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 . 
         [0032]    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. 
         [0033]    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.