Abstract:
A method of making a carbon nanotube reinforced solder cap. Carbon nanotube-solder (CNT-S) particles are transferred from a transfer substrate, having an adhesive layer, to a solder bump by using thermo compression bonding. The CNT-S particles are then reflowed to form a cap on the solder bump. The solder bump with the reflowed cap can then be joined to a bonding pad or another solder bump with a cap by placing the solder bump on the pad or other bump and reflowing at a temperature sufficient to reflow the cap(s).

Description:
TECHNICAL FIELD 
     Embodiments relate generally to integrated circuit fabrication. More particularly, embodiments relate to solder cap materials in connection with microelectronic devices. 
     TECHNICAL BACKGROUND 
     Solders are an important part of a packaged integrated circuit (IC). An IC die is often fabricated into a microelectronic device such as a processor. The solders complete couplings between the IC die and the outside world. 
     The increasing demands upon an IC to perform at high speeds and to not overheat presents problems for the solders. The increasing heat stresses in an IC package causes thermal stresses between the solders and the substrates to which the solders are bonded. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       In order to depict the manner in which the embodiments are obtained, a more particular description of embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in 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, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is a process depiction during formation of carbon nanotube-impregnated solder particles according to an embodiment; 
         FIG. 2  is a cross-section elevation of a package that includes a micro solder cap disposed upon a metal bump according to an embodiment; 
         FIG. 3  is a cross-section elevation of a package that includes a carbon nanotube solder cap disposed upon a metal bump according to an embodiment; 
         FIG. 4A  is a cross-section elevation of preparing a carbon nanotube solder particle for bonding according to an embodiment; 
         FIG. 4B  is a cross-section elevation of preparing the carbon nanotube solder particle depicted in  FIG. 4A  after further processing according to an embodiment; 
         FIG. 4C  is a cross-section elevation of preparing the carbon nanotube solder particle depicted in  FIG. 4B  after further processing; 
         FIG. 4D  is a cross-section elevation of preparing the carbon nanotube solder particle depicted in  FIG. 4C  after further processing; 
         FIG. 5A  is a cross-section elevation of thermo compression bonding a carbon nanotube solder particle according to an embodiment; 
         FIG. 5B  is a cross-section elevation of thermo compression bonding the carbon nanotube solder particle depicted in  FIG. 5A  after further processing according to an embodiment; 
         FIG. 5C  is a cross-section elevation the carbon nanotube solder particle depicted in  FIG. 5B  after thermo compression bonding; 
         FIG. 6(   a ) is a computer-image depiction of a photomicrograph that exhibits carbon nanotube solder particles disposed upon a metal bump according to an embodiment; 
         FIG. 6(   b ) is a computer-image cross-section elevation depiction of a photomicrograph that exhibits a carbon nanotube solder particle disposed upon a metal bump according to an embodiment; 
         FIG. 7A  is a cross-section elevation of a carbon nanotube solder particle after thermo compression bonding according to an embodiment; 
         FIG. 7B  is a cross-section elevation of the structure depicted in  FIG. 7A  after solder cap reflow according to an embodiment; 
         FIG. 8(   a ) is a computer-image depiction of a photomicrograph that exhibits reflowed carbon nanotube solder particles disposed upon a metal bump according to an embodiment; 
         FIG. 8(   b ) is a computer-image cross-section elevation depiction of a photomicrograph that exhibits reflowed carbon nanotube solder particles disposed upon a metal bump according to an embodiment; 
         FIG. 9A  is a cross-section elevation of a structure after solder cap reflow according to an embodiment; 
         FIG. 9B  is a computer-image cross-section elevation depiction of a photomicrograph that exhibits a solder-cap-on-solder-cap configuration of carbon nanotube solder particles disposed upon metal bumps according to an embodiment; 
         FIG. 10  is a cross-section elevation of a chip package that exhibits a solder-cap-on-solder-cap configuration of carbon nanotube solder particles disposed upon metal bumps according to an embodiment; 
         FIG. 11A  is a cross-section elevation of a structure after solder cap reflow according to an embodiment; 
         FIG. 11B  is a computer-image cross-section elevation depiction of a photomicrograph that exhibits a solder-cap-on-bond-pad configuration of carbon nanotube solder particles disposed upon a metal bump according to an embodiment; 
         FIG. 12  is a cross-section elevation of a chip package that exhibits a solder-cap-on-bond-pad configuration of carbon nanotube solder particles disposed upon a metal bump according to an embodiment; 
         FIG. 13  is a process flow depiction of forming a carbon nanotube solder cap according to an embodiment; 
         FIG. 14  is a cut-away elevation that depicts a computing system according to an embodiment; and 
         FIG. 15  is a schematic of a computing system according to an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     Embodiments in this disclosure relate to a carbon nanotube solder (CNT-S) cap that is coupled to an IC substrate. One way to improve electrical and heat conductivity is to improve the electrical and heat conductivity in the solder bumps that are used to connect an IC package. Bonding of a CNT-S particle is done at a temperature that approaches the homologous temperature. 
     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 an apparatus or article described herein can be manufactured, used, or shipped in a number of positions and orientations. 
     Reference will now be made to the drawings wherein like structures will be provided with like suffix reference designations. In order to show the structures of various embodiments most clearly, the drawings included herein are diagrammatic representations of integrated circuit structures. Thus, the actual appearance of the fabricated structures, for example in a photomicrograph, may appear different while still incorporating the essential structures of the illustrated embodiments. Moreover, the drawings show only the structures necessary to understand the illustrated embodiments. Additional structures known in the art have not been included to maintain the clarity of the drawings. 
       FIG. 1  is a process depiction  100  during formation of carbon nanotube-impregnated solder particles according to an embodiment. A CNT reservoir  110  contains a collection of CNT fibers  112  that are to be mingled with solder. A solder crucible  114  contains molten solder  116 . An atomizing gas is introduced at a gas-liquid orifice  118  that causes the molten solder to atomize into particles in a size range from about 5 nanometer (nm) to about 15 nm. In an embodiment, an average particle size that is formed during atomizing of the molten solder  116  is about 6 nm. In an embodiment and in order to prevent premature solidification of the molten solder  116  that is being atomized, the atomizing gas is preheated. In an embodiment, a coil heat exchanger preheats the atomizing gas by economizing heat exchange with the molten solder  116 , such that the atomizing gas is virtually the same temperature as the molten solder  116  as it exits at the gas-liquid orifice  118 . The atomizing gas can be a non-reactive gas such as argon (Ar) or other non-reactive gases. 
     After atomizing the molten solder  116  at the gas-liquid orifice  118 , the CNT fibers  112  are injected into the atomized solder in a falling mixture  120 . In an embodiment, the temperature of the CNT fibers  112  is slightly below that of the atomized solder, such that the CNT fibers  112  have a cooling and solidifying effect upon the falling solder. The falling mixture  120  is contained within a chamber  122  and it accumulates into a plurality of CNT-S particles  124 . The CNT fibers have a dimension of about 2-8 nm in length according to an embodiment. 
     In an embodiment, the solder  116  is a copper-based solder such as pure copper, copper-tin, copper-tin-lead, copper-tin-silver, copper-tin-bismuth, copper-tin-indium and others. 
     In an embodiment, the solder  116  is a nickel-based solder such as pure nickel, nickel-tin, nickel-tin-lead, nickel-tin-silver, nickel-tin-bismuth, nickel-tin-indium and others. In an embodiment, the solder  116  is a nickel-titanium shape-memory alloy such as NITINOL®, manufactured by Johnson-Matthey of Wayne, Pa. 
     In an embodiment, the solder  116  is a tin-based solder such as pure tin, tin-nickel, tin-lead, tin-indium, tin-lead-nickel, tin-nickel-silver, and others. In an embodiment, the solder  116 , by weight percent, is approximately Sn-10 In-0.6 Cu. In this depiction, the solder  116  includes about 10 percent indium, about 0.6 percent copper, and the balance tin. Other impurities may be present, based upon the specific feedstocks obtained and the chemical purities thereof. 
     In an embodiment, the solder  116  is an indium-based solder such as pure indium, indium-tin, indium-lead, indium-lead-nickel, indium-nickel-silver, and others. 
       FIG. 2  is a cross-section elevation of a package  200  that includes a microsolder cap  210  disposed upon a metal bump  212  according to an embodiment. A bonding pad  214  supports the metal bump  212 . A substrate  216  supports the metal bump  212 . The bonding pad  214  is exposed through a solder mask  218 . In an embodiment, the bond pad  214  includes a flash layer  220 , such as a gold flash layer upon a copper bond pad. 
     In an embodiment, the substrate  216  is an IC die. In an embodiment, the substrate  216  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the substrate  216  is a board such as a motherboard. 
     In an embodiment, the size of the metal bump  212  can be ascertained by the size of the bond pad  214 . In an embodiment, the bond pad  214  is about 106 micrometers (μm). Other dimensions can be selected depending upon the application. For example, spacing  220  between centers of bond pads  214  can be less than about 100 μm. In an embodiment, spacing  220  between centers of bond pads  214  is about 90 μm. 
     In an embodiment, the solder cap  210  is derived from a nano-particulate solder paste, about 100 percent of which pass the 20 nm screening, and the matrix includes a paste such as a fluxing agent and a volatile component. After reflow, the microsolder cap  210  exhibits an average grain size of about 20 μm. 
       FIG. 3  is a cross-section elevation of a package  300  that includes a carbon nanotube solder cap  310  disposed upon a metal bump  312  according to an embodiment. A bonding pad  314  supports the metal bump  312 . A substrate  316  supports the metal bump  312 . The bonding pad  314  is exposed through a solder mask  318 . A network  322  of carbon nanotubes is dispersed in the solder cap  310 . In an embodiment, the network  322  of carbon nanotubes is present in the solder of the solder cap  310  in a range from about 1 to about 99 volume percent of the solder cap  310 . In an embodiment, the network  322  of carbon nanotubes is present in the solder of the solder cap  310  in a range from about 10 to about 70 volume percent. In an embodiment, the network  322  of carbon nanotubes is present in the solder of the solder cap  310  in a range from about 20 to about 50 volume percent. In an embodiment, the network  322  of carbon nanotubes is present in the solder of the solder cap  310  in a range from about 30 to about 40 volume percent. 
     In an embodiment, the bonding pad  314  includes a flash layer  320 , such as a gold flash layer upon a copper bond pad. In an embodiment, the substrate  316  is an IC die. In an embodiment, the substrate  316  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the substrate  316  is a board such as a motherboard. 
     In an embodiment, the size of the metal bump  312  can be ascertained by the size of the bond pad  314 . In an embodiment, the bond pad  314  is about 106 μm. Other dimensions can be selected depending upon the application. For example, spacing  320  between centers of bond pads  314  can be less than about 100 μm. In an embodiment, spacing  320  between centers of bond pads  314  is about 90 μm. 
       FIG. 4A  is a cross-section elevation of a method  400  for preparing a carbon nanotube solder particle for bonding according to an embodiment. A rigid substrate  424  has received a layer of CNT-S particles  410  according to any of the embodiments set forth in this disclosure. In an embodiment, the CNT-S particles  410  form a monolayer over the rigid substrate  424 , such that a monolayer can be transferred to a metal bump. Accordingly, the monolayer of CNT-S particles  412  will form a micro CNT-S cap that is proportional to the particle size of the CNT-S particles  412 . 
       FIG. 4B  is a cross-section elevation of the method for preparing the carbon nanotube solder particle depicted in  FIG. 4A  after further processing according to an embodiment. The method  401  illustrates a flexible sheet  426  being brought toward the CNT-S particles  410 . The flexible sheet  426  has an adhesive  428 . 
       FIG. 4C  is a cross-section elevation of preparing the carbon nanotube solder particle depicted in  FIG. 4B  after further processing. The method  402  illustrates the flexible sheet  426  being pressed against the CNT-S particles  410 . Consequently, a transfer of the CNT-S particles  410  is achieved by the adhesive  428  picking up the CNT-S particles  410  from the surface of the rigid substrate  424 . 
       FIG. 4D  is a cross-section elevation of preparing the carbon nanotube solder particle depicted in  FIG. 4C  after further processing. The method  403  illustrates the flexible sheet  426  being drawn away from the rigid substrate  424  with the CNT-S particles  410  affixed to the adhesive  428  and the flexible sheet  426 . 
       FIG. 5A  is a cross-section elevation of thermo compression bonding a carbon nanotube solder particle according to an embodiment. A bonding pad  514  supports a metal bump  512 . A substrate  516  supports the bonding pad  514 . The bonding pad  514  is exposed through a solder mask  518 . 
     A flexible sheet  526  and an adhesive  528  hold a layer of CNT-S particles  510  that includes a network of carbon nanotubes dispersed in the CNT-S particles  510 . The process  500  is illustrated with a thermal compression head  530  depicted being brought close to the metal bump  512 , with the CNT-S particles  510  approaching the metal bump  512 . 
       FIG. 5B  is a cross-section elevation of thermo compression bonding the carbon nanotube solder particle depicted in  FIG. 5A  after further processing according to an embodiment. The process  501  is further illustrated with the thermal compression head  530  pressing the CNT-S particles  510  against the metal bump  512 . In an embodiment, the temperature of the CNT-S particles  510  is controlled not to exceed the melting point of thereof. Particularly because compression can cause heating, as well as thermal flux being driven out of the thermal compression head  530  such as by an electrical coil contained therein, temperature control takes both heating effects into account. In an embodiment, the temperature of the CNT-S particles  510  does not exceed about 99 percent of the homologous temperature, which is the achieved temperature (in absolute scale) divided by the solidus temperature. In other words, the solidus temperature, which is the temperature at which a solid starts to become a liquid at standard atmospheric pressure, is not reached. In an embodiment, the temperature of the CNT-S particles  510  does not exceed about 99.9 percent of the homologous temperature. 
       FIG. 5C  is a cross-section elevation of the carbon nanotube solder particle depicted in  FIG. 5B  after thermo compression bonding. The process  502  is further illustrated with the thermal compression head  530  retracting from the CNT-S particles, some of which CNT-S particles  511  remain disposed against the metal bump  512 , and some of which CNT-S particles  510  remain disposed against the adhesive  528 . 
       FIG. 6A  is a computer-image depiction of a photomicrograph  600  that exhibits carbon nanotube solder particles  611  disposed upon a metal bump  612  according to an embodiment. The CNT-S particles  611  have been thermal compression bonded to the metal bump  612 . 
       FIG. 6B  is a computer-image cross-section elevation depiction of a photomicrograph  601  that exhibits a carbon nanotube solder particle  611  disposed upon a metal bump  612  according to an embodiment. The computer-image of  FIG. 6B  is more enlarged than the computer-image of  FIG. 6A . The CNT-S particle  611  shows a thermal compression bond line  632  between the CNT-S particle  611  and the metal bump  612 . 
       FIG. 7A  is a cross-section elevation of a carbon nanotube solder particle after thermo compression bonding according to an embodiment. A package  700  is illustrated with some CNT-S particles  711  remaining thermal compression bonded against a metal bump  712 . A bonding pad  714  supports the metal bump  712 . A substrate  716  supports the bonding pad  714 . The bonding pad  714  is exposed through a solder mask  718 . 
       FIG. 7B  is a cross-section elevation of the structure depicted in  FIG. 7A  after solder cap reflow according to an embodiment. The package  701  is illustrated after reflow of CNT-S particles into a CNT-S microcap  710 . 
       FIG. 8A  is a computer-image depiction of a photomicrograph  800  that exhibits reflowed carbon nanotube solder particles disposed upon a metal bump according to an embodiment. Reflowed CNT-S particles have formed a CNT-S microcap  810 , disposed and bonded to a metal bump  812 . 
       FIG. 8B  is a computer-image cross-section elevation depiction of a photomicrograph  801  that exhibits reflowed carbon nanotube solder particles disposed upon a metal bump according to an embodiment. The cross section shows the CNT-S microcap  810 , the metal bump  812 , and penetration of a portion of the metal bump  812  onto a bonding pad  814 . 
       FIG. 9A  is a cross-section elevation of a package  900  after solder cap reflow according to an embodiment. In a first structure  908 , a first CNT-S microcap  910  is disposed upon a first metal bump  912 . A first bonding pad  914  supports the first metal bump  912 . A first substrate  916  supports the first bonding pad  914 . The first bonding pad  914  is exposed through a first solder mask  918 . In an embodiment, the first substrate  916  is an IC die. In an embodiment, the first substrate  916  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the first substrate  916  is a board such as a motherboard. 
     In a second structure  906 , a second CNT-S microcap  950  is disposed upon a second metal bump  952 . A second bonding pad  954  supports the second metal bump  952 . A second substrate  956  supports the second bonding pad  954 . The second bonding pad  954  is exposed through a second solder mask  958 . In an embodiment, the second substrate  956  is an IC die. In an embodiment, the second substrate  956  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the second substrate  956  is a board such as a motherboard. 
     The package  900  is depicted being brought together such that the first metal bump  912  and the second metal bump  952  are to be in direct contact with the first solder cap  910 . Similarly, the first metal bump  912  and the second metal bump  952  are to be in direct contact with the second solder cap  950 . This is because the first solder cap  910  and the second solder cap  950  are to meld and form a continuous reflowed CNT-S microcap. 
     Processing of the first solder cap  910  and the second solder cap  950  can be done by heating the solder cap materials to a low temperature at which the solder cap materials begin to reflow. 
       FIG. 9B  is a computer-image cross-section elevation depiction of a photomicrograph  901  that exhibits a solder-cap-on-solder-cap configuration of carbon nanotube solder particles disposed upon metal bumps according to an embodiment. After bringing the structures  908  and  906  together ( FIG. 9A ), and after reflowing the two CNT-S microcaps  910  and  950 , a structure results that is a configuration of the first CNT-S microcap  910  disposed and melded with the second CNT-S microcap  950 . The conjoined CNT-S microcaps  910  and  950  appear in  FIG. 9B  as a bond line  960 . 
       FIG. 10  is a cross-section elevation of a chip package  1000  that exhibits a solder-cap-on-solder-cap configuration of carbon nanotube solder particles disposed upon metal bumps according to an embodiment. 
     In a first structure  1008 , a first CNT-S microcap  1010  is disposed upon a first metal bump  1012 . A first bonding pad  1014  supports the first metal bump  1012 . A first substrate  1016  supports the first bonding pad  1014 . In an embodiment, the first substrate  1016  is a mounting substrate such as for mounting a flip-chip IC die. 
     In a second structure  1006 , a second CNT-S microcap  1050  is disposed upon a second metal bump  1052 . A second bonding pad  1054  supports the second metal bump  1052 . A second substrate  1056  supports the second bonding pad  1054 . In an embodiment, the second substrate  1056  is an IC die that is flip-chip mounted to the first substrate  1016 . 
       FIG. 11A  is a cross-section elevation of a package  1100  after solder cap reflow according to an embodiment. In a first structure  1108 , a first bonding pad  1114  is disposed on a first substrate  1116 . The first bonding pad  1114  is exposed through a first solder mask  1118 . In an embodiment, the first substrate  1116  is an IC die. In an embodiment, the first substrate  1116  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the first substrate  1116  is a board such as a motherboard. 
     In a second structure  1106 , a second CNT-S microcap  1150  is disposed upon a second metal bump  1152 . A second bonding pad  1154  supports the second metal bump  1152 . A second substrate  1156  supports the second bonding pad  1154 . The second bonding pad  1154  is exposed through a second solder mask  1158 . In an embodiment, the second substrate  1156  is an IC die. In an embodiment, the second substrate  1156  is a mounting substrate such as for mounting a flip-chip IC die. In an embodiment, the second substrate  1156  is a board such as a motherboard. 
     The package  1100  is depicted being brought together such that the first bonding pad  1114  and the second metal bump  1152  are to be in direct contact with the second solder cap  1150 . This is because the first bonding pad  1114  and the second solder cap  1150  are to meld and form a continuous reflowed CNT-S microcap. 
     Processing of the second solder cap  1150  can be done by heating the solder cap materials to a low temperature at which the solder cap materials begin to reflow. 
       FIG. 11B  is a computer-image cross-section elevation depiction of a photomicrograph  1101  that exhibits a solder-cap-on-solder-cap configuration of carbon nanotube solder particles disposed upon a metal bump according to an embodiment. After bringing the structures  1108  and  1106  together ( FIG. 11A ), and after reflowing the second CNT-S microcap  1150 , a structure results that is a configuration of the first bonding pad  1114  with the second CNT-S microcap  1150  disposed and melded therewith, and also with the second bonding pad  1154 . 
       FIG. 12  is a cross-section elevation of a chip package  1200  that exhibits a solder-cap  1250  on a bond pad  1254  configuration of carbon nanotube solder particles disposed upon a metal bump  1252  according to an embodiment. 
     In a first structure  1208 , a first substrate  1216  supports a first bonding pad  1214 . In an embodiment, the first substrate  1216  is a mounting substrate such as for mounting a flip-chip IC die. 
     A second CNT-S microcap  1250  is disposed upon a metal bump  1252 . A second bonding pad  1254  supports the second metal bump  1252 . A second substrate  1256  supports the second bonding pad  1254 . In an embodiment, the second substrate  1256  is an IC die that is flip-chip mounted to the second substrate  1256 . 
       FIG. 13  is a process flow  1300  depiction of forming a carbon nanotube solder cap according to an embodiment. 
     At  1308 , the process includes mingling CNT fibers with an atomized solder to form a CNT-S particle. 
     At  1310 , the process includes forming a plurality of CNT-S particles upon a rigid substrate. 
     At  1312 , the process includes forming a monolayer of CNT-S particles upon a rigid substrate. 
     At  1314 , the process includes affixing the CNT-S composite particles upon an adhesive that is backed by a transfer substrate. 
     At  1320 , the process includes thermo compression transfer bonding the CNT-S composite particle from a transfer substrate to a metal bump. In an embodiment, the process commences and terminates at  1320 . 
     At  1322 , the process includes the thermo compression transfer bonding at a temperature that is below the homologous temperature of the CNT-S. In an embodiment, the process commences at  1320  and terminates at  1322 . 
     At  1330 , the process includes reflowing the CNT-S upon the metal bump to form a CNT-S microcap. In an embodiment, the process commences at  1320  and terminates at  1330 . 
     At  1340 , the process includes bonding the reflowed CNT-S microcap to one of a second metal bump and a bonding pad. In an embodiment, the process commences at  1308  and terminates at  1340 . In an embodiment, the process commences at  1310  and terminates at  1340 . In an embodiment, the process commences at  1320  and terminates at  1340 . In an embodiment, the process commences and terminates at  1340 . 
       FIG. 14  is a cut-away elevation that depicts a computing system  1400  according to an embodiment. One or more of the foregoing embodiments of the CNT-S microcaps may be utilized in a computing system, such as a computing system  1400  of  FIG. 14 . Hereinafter any CNT-S microcap embodiments alone or in combination with any other embodiment can be referred to as an embodiment(s) configuration. 
     The computing system  1400  includes at least one IC processor, which is enclosed in a package  1410 , a data storage system  1412 , at least one input device such as a keyboard  1414 , and at least one output device such as a monitor  1416 , for example. The computing system  1400  includes a processor that processes data signals, and may include, for example, a microprocessor, available from Intel Corporation. In addition to the keyboard  1414 , the computing system  1400  can include another user input device such as a mouse  1418 , for example. 
     For purposes of this disclosure, a computing system  1400  embodying components in accordance with the claimed subject matter may include any system that utilizes a microelectronic device system, which may include, for example, at least one of the CNT-S microcap embodiments that is coupled to data storage such as dynamic random access memory (DRAM), polymer memory, flash memory, and phase-change memory. In this embodiment, the embodiment(s) is coupled to any combination of these functionalities by being coupled to a processor. In an embodiment, however, an embodiment(s) configuration set forth in this disclosure is coupled to any of these functionalities. For an example embodiment, data storage includes an embedded DRAM cache on a die. Additionally in an embodiment, the embodiment(s) configuration that is coupled to the processor (not pictured) is part of the system with an embodiment(s) configuration that is coupled to the data storage of the DRAM cache. Additionally in an embodiment, an embodiment(s) configuration is coupled to the data storage system  1412 . 
     In an embodiment, the computing system  1400  can also include a die that contains a digital signal processor (DSP), a micro controller, an application specific integrated circuit (ASIC), or a microprocessor. In this embodiment, the embodiment(s) configuration is coupled to any combination of these functionalities by being coupled to a processor. For an example embodiment, a DSP (not pictured) is part of a chipset that may include a stand-alone processor and the DSP as separate parts of the chipset on a board  1420 . In this embodiment, an embodiment(s) configuration is coupled to the DSP, and a separate embodiment(s) configuration may be present that is coupled to the processor in the package  1410 . Additionally in an embodiment, an embodiment(s) configuration is coupled to a DSP that is mounted on the same board  1420  as the package  1410 . It can now be appreciated that the embodiment(s) configuration can be combined as set forth with respect to the computing system  1400 , in combination with an embodiment(s) configuration as set forth by the various embodiments of the CNT-S microcaps within this disclosure and their equivalents. 
       FIG. 15  is a schematic of a computing system according to an embodiment. The electronic system  1500  as depicted can embody the computing system  1400  depicted in  FIG. 14 , including a CNT-S microcap embodiment, but the electronic system is depicted more generically. The electronic system  1500  incorporates at least one electronic assembly  1510 , such as an IC package illustrated in  FIGS. 9A ,  10 ,  11 A, and  12 . In an embodiment, the electronic system  1500  is a computer system that includes a system bus  1520  to electrically couple the various components of the electronic system  1500 . The system bus  1520  is a single bus or any combination of busses according to various embodiments. The electronic system  1500  includes a voltage source  1530  that provides power to the integrated circuit  1510 . In some embodiments, the voltage source  1530  supplies current to the integrated circuit  1510  through the system bus  1520 . 
     The integrated circuit  1510  is electrically coupled to the system bus  1520  and includes any circuit, or combination of circuits according to an embodiment. In an embodiment, the integrated circuit  1510  includes a processor  1512  that can be of any type. As used herein, the processor  1512  means any type of circuit such as, but not limited to, a microprocessor, a microcontroller, a graphics processor, a digital signal processor, or another processor. Other types of circuits that can be included in the integrated circuit  1510  are a custom circuit or an ASIC, such as a communications circuit  1514  for use in wireless devices such as cellular telephones, pagers, portable computers, two-way radios, and similar electronic systems. In an embodiment, the integrated circuit  1510  includes on-die memory  1516  such as SRAM. In an embodiment, the integrated circuit  1510  includes on-die memory  1516  such as eDRAM. 
     In an embodiment, the electronic system  1500  also includes an external memory  1540  that in turn may include one or more memory elements suitable to the particular application, such as a main memory  1542  in the form of RAM, one or more hard drives  1544 , and/or one or more drives that handle removable media  1546  such as diskettes, compact disks (CDs), digital video disks (DVDs), flash memory keys, and other removable media known in the art. 
     In an embodiment, the electronic system  1500  also includes a display device  1550 , an audio output  1560 . In an embodiment, the electronic system  1500  includes a controller  1570 , such as a keyboard, mouse, trackball, game controller, microphone, voice-recognition device, or any other device that inputs information into the electronic system  1500 . 
     As shown herein, integrated circuit  1510  can be implemented in a number of different embodiments, including an electronic package, an electronic system, a computer system, one or more methods of fabricating an integrated circuit, and one or more methods of fabricating an electronic assembly that includes the integrated circuit and the foamed-solder embodiments as set forth herein in the various embodiments and their art-recognized equivalents. The elements, materials, geometries, dimensions, and sequence of operations can all be varied to suit particular packaging requirements. 
     It can now be appreciated that CNT-S microcap 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(s) configuration, 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 that can be packaged with an embodiment(s) configuration and placed in a vehicle such as an automobile, a locomotive, a watercraft, an aircraft, or a spacecraft. 
     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. 
     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. 
     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 that 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.