Patent Publication Number: US-9419339-B2

Title: Package structures including discrete antennas assembled on a device

Description:
This is a Continuation application of Ser. No. 13/721,245 filed Dec. 20, 2012, which is presently pending. 
    
    
     BACK GROUND OF THE INVENTION 
     The integration of millimeter wave radios operating at 30 GHz or above on platforms allows for the wireless transfer of data between devices or between chips. The successful transfer of data between the devices/chips requires one or more package-level integrated antennas that serve as an interface. Applications such as ultra-short range chip-to-chip communications and post silicon validation of system on a chip(SoC)/central processing unit (CPU) devices using wireless debug ports may suffer from routing losses and loss of package real estate associated with traditional/prior art in package substrate/antenna array designs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming certain embodiments, the advantages of these embodiments can be more readily ascertained from the following description of the invention when read in conjunction with the accompanying drawings in which: 
         FIGS. 1 a -1 d    represent structures according to various embodiments. 
         FIG. 2  represents a flow chart according to embodiments. 
         FIG. 3  represents structures according to embodiments. 
         FIG. 4  represents a system according to embodiments. 
     
    
    
     DETAILED DESCRIPTION OF THE PRESENT INVENTION 
     In the following detailed description, reference is made to the accompanying drawings that show, by way of illustration, specific embodiments in which the methods and structures may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the embodiments. It is to be understood that the various embodiments, although different, are not necessarily mutually exclusive. For example, a particular feature, structure, or characteristic described herein, in connection with one embodiment, may be implemented within other embodiments without departing from the spirit and scope of the embodiments. In addition, it is to be understood that the location or arrangement of individual elements within each disclosed embodiment may be modified without departing from the spirit and scope of the embodiments. The following detailed description is, therefore, not to be taken in a limiting sense, and the scope of the embodiments is defined only by the appended claims, appropriately interpreted, along with the full range of equivalents to which the claims are entitled. In the drawings, like numerals may refer to the same or similar functionality throughout the several views. 
     Methods of forming and utilizing microelectronic package structures, such as forming a package structure including discrete antenna disposed on a top surface of a microelectronic device, are described. Those methods and structures may include forming a package structure comprising a discrete antenna disposed on a back side of a device, wherein the discrete antenna comprises an antenna substrate, a through antenna substrate via vertically disposed through the antenna substrate. A through substrate via that is vertically disposed within the device may be coupled with the through antenna substrate via, and a package substrate may be coupled with an active side of the device. The package structures of the various embodiments disclosed herein enable the use of discrete individual antennas for shorter range transmission applications. 
       FIGS. 1 a -1 d    illustrate embodiments of package structures including at least one discrete antenna disposed on a device. In an embodiment, a package structure  100  comprises at least one discrete antenna  102  ( FIG. 1 a   ). The discrete antenna  102  comprises an antenna substrate  104 , which may comprise a glass material in some embodiments. In other embodiments, the antenna substrate  104  may comprise at least one of a liquid crystal polymer, an organic material, a low temperature co-fired ceramic, alumina, an undoped silicon, and any high performance, millimeter wave substrate, depending upon the particular application. In an embodiment, the antenna substrate  104  comprises a frequency of about 30 GHz and above. In an embodiment, the antenna substrate  104  may comprise alternating layers of conductive material and dielectric material. In an embodiment, the discrete antenna  102  may comprise a high k dielectric material, which may serve to reduce the dimensions of the discrete antenna  102 , in some cases. In an embodiment, the discrete antenna  102  may comprise a radiating element  106  and a through antenna substrate via  108 . In an embodiment, the radiating element  106  may comprise multiple levels of metals that may be capacitavely coupled to each other (for example, the radiating element may comprise a plurality of metal layers separated by dielectric material) to enhance the frequency bandwidth of the discrete antenna  102 . 
     In an embodiment, the radiating element  106  may be horizontally disposed on a top portion of the antenna substrate  104 , and may be perpendicularly coupled with the through antenna substrate via  108 . In an embodiment, the discrete antenna  102  may comprise dimensions that may be less than about 2 mm in width, less than about 2 mm in length and less than about 0.4 mm in height. The dimensions of the discrete antenna  102  may vary depending upon the particular application. In an embodiment, the physical dimensions of the antenna substrate  104  may be much less than the wavelength of the frequency range within which the device/application is capable of operating. In an embodiment, the through antenna substrate via  108  may not be physically coupled to the radiating element  106 , wherein a milliwave-wave signal may be electromagnetically coupled between the radiating element  106  and a through substrate via  116 . 
     The through antenna substrate via  108  may be vertically disposed within the antenna substrate  104 . An antenna contact  110  may be coupled with the through antenna substrate via  108 , and may be disposed on a bottom portion of the antenna substrate  104 . An antenna conductive structure  112  may be coupled with the antenna contact  110 . A device contact  114 , which may comprise a redistribution layer (RDL)  114 , may be coupled with the antenna conductive structure  112 . The device contact  114  may be disposed on a backside of a device  118 . The device  118  may comprise a system on chip (SoC) device comprising a radio  119 , such as a millimeter wave radio, in an embodiment, and may comprise any type of device suitable for a particular application, in other embodiments. 
     A through device substrate via, which may comprise a through substrate via (TSV)  116  may be coupled with the device contact  114 , and may be vertically disposed within the device/device substrate  118 . In an embodiment, the through substrate via  116  may be lined with an insulator material  121 , such as silicon oxide, for example ( FIG. 1 d   , depicting a portion of the device  118  comprising the TSV  116 ). The through substrate via  116  lined with the insulator  121  may be disposed through a device material  135 , which may comprise a silicon substrate material  135  in some cases, and the device  118  may exhibit losses of less than 1 dB in embodiments. The device material  135  may be insulated from the device contact  114  and an active layer/side  120  of the device  118  by an insulating material  137  such as an oxide material, for example. 
     Referring back to  FIG. 1 a   , the through substrate via  116  may be electrically and physically coupled with the through antenna substrate via  108  (with antenna contact  110 , the conductive structure  112  and the device contact  114  coupling in between), wherein the through antenna substrate via  108  coupled with the through substrate via  116  may conduct a signal from the discrete antenna  102  to the device  118 . In another embodiment, the through antenna substrate via  108  may be coupled to the through substrate via  116  by one of a conductive structure and metal to metal bonding. In an embodiment, the discrete antenna  102  may comprise a high performance millimeter wave antenna substrate  104  such as glass. The millimeter wave signal that is capable of being emitted/propagated from the radiating element  106  in/on the antenna substrate  104  may be transmitted/propagated between the discrete antenna  102  and the device  118  by the coupling between the through antenna substrate via  108  and the through substrate via  116 . 
     A ground antenna contact  111  may be disposed on the bottom portion of the antenna substrate  104 , adjacent the antenna contact  110 . A ground antenna conductive structure  113  may be coupled with the ground antenna contact  111 . A ground device contact  115  may be coupled with the ground antenna conductive structure  113 . The ground device contact  115  may be disposed on a backside of the device  118 . A ground through device substrate via  117 , which may comprise a ground through substrate via  117 , may be coupled with the ground device contact  115 , and may be vertically disposed within the device  118 . The ground through device substrate via  117  may be adjacent to the signal through substrate via  116 , and may provide ground referencing to the discrete antenna  102 . 
     In an embodiment, a second discrete antenna  102 ′ may be disposed on the device  118  and may be adjacent to the discrete antenna  102 . The second discrete antenna  102 ′ comprises an antenna substrate  104 ′, and may comprise similar materials as the antenna substrate  104 . The second discrete antenna  102 ′ may comprise a radiating element  106 ′ coupled to a through antenna substrate via  108 ′, an antenna contact  110 ′ coupled with the through antenna substrate via  108 ′, and an antenna conductive structure  112 ′ coupled with the antenna contact  110 ′. 
     A device contact  114 ′ may be coupled with the antenna conductive structure  112 ′. The device contact  114 ′ may be disposed on a backside of the device  118 . A through device substrate via  116 ′ may be coupled with the device contact  114 ′, and may be vertically disposed within the device  118 . The through device substrate via  116 ′ may be electrically and physically coupled with the through antenna substrate via  108 ′. 
     A ground antenna contact  111 ′ may be disposed on the bottom portion of the antenna substrate  104 ′, adjacent the antenna contact  110 ′. A ground antenna conductive structure  113 ′ may be coupled with the ground antenna contact  111 ′. A ground device contact  115 ′ may be coupled with the ground antenna conductive structure  113 ′. The ground device contact  115 ′ may be disposed on a backside of the device  118 . A ground through substrate via  117 ′, which may comprise a ground through device substrate via  117 ′, may be coupled with the ground device contact  115 ′, and may be vertically disposed within the device  118 . The ground through substrate via  117 ′ may be adjacent to the signal through substrate via  116 ′, and may ground reference to the second discrete antenna  102 ′. 
     The discrete antennas  102 ,  102 ′ may be assembled/coupled with the back side of the device  118 . In an embodiment, a millimeter wave signal that may be induced between the device and the discrete antennas  102 ,  102 ′ by the radiating elements  106 ,  106 ′ may be carried by a series connection between the signal through the substrate vias  116 ,  116 ′ and the through antenna substrate vias  108 ,  108 ′. Additionally, each of the signal vias (which may comprise the series connection between the through the substrate vias  116 ,  116 ′ and the through antenna substrate vias  108 ,  108 ′) may be surrounded by one or multiple ground through substrate vias  117 ,  117 ′, depending upon the particular application. The ground through substrate vias  117 ,  117 ′ serve as a return path for the millimeter wave signal from the discrete antennas  102 ,  102 ′. 
     The discrete antennas  102 ,  102 ′ exhibit greatly improved electrical properties as compared with antennas implemented within a package substrate. In addition, the vertical implementation of the TSV&#39;s coupled with the vertical through antenna substrate vias frees up package space needed for traditional CPU signal routing, for example, and hence improves the overall compactness of the package structure  100 . 
     In an embodiment, the active side/layer  120  of the device  118  may be coupled with a substrate  126  by solder balls/interconnects  122 . In another embodiment, the active side  120  of the device  118  may be coupled with the substrate  126  by direct metal to metal bonding. In an embodiment, the package structure  100  may comprise a 3D package structure  100 . In an embodiment, the package structure  100  may comprise a portion of a coreless, bumpless build up layer (BBUL) package structure  100 . In another embodiment, the portion of the package structure  100  may comprise any suitable type of package structure  100  capable of providing electrical communications between a microelectronic device(s), such as the devices  102 ,  102 ′ 102 ″, and a next-level component to which the package structure  100  may be coupled (e.g., a circuit board). In another embodiment, the package structures  100  herein may comprise any suitable type of package structures capable of providing electrical communication between a die and an upper integrated circuit (IC) package coupled with a lower IC package. 
     The substrate  126  of the embodiments herein may comprise a multi-layer substrate  126 , including alternating layers of a dielectric material and metal built-up around a core layer (either a dielectric or metal core). In another embodiment, the substrate  126  may comprise a coreless multi-layer substrate  126 . Other types of substrates and substrate materials may also find use with the disclosed embodiments (e.g., ceramics, sapphire, glass, etc.). 
     In an embodiment, the device package structure  100  comprises the device  118  including the millimeter wave radio  119 , that may be flip-chip assembled on a multilayer package substrate  126 . In another embodiment, a plurality of discrete chip antennas  102  may be formed/coupled on the device  118 , wherein the number of discrete antennas  102  coupled with the device  118  may depend upon the particular design requirements. The discrete antennas  102  of the embodiments herein occupy less area on the package substrate  126 , and exhibit a significant decrease in signal loss. Additionally, the embodiments require less stringent signal isolation solution, leading to a decrease of package footprint. 
       FIG. 1 b    depicts an embodiment wherein the device  118  (similar to the device  118  and associated package  100  components depicted in  FIG. 1 a   ) may be partially embedded in a coreless substrate  127 , such as a BBUL substrate  127 , for example. Interconnects  122  may be disposed within the substrate  127  and may be coupled with coreless interconnect structures  124 . In an embodiment, the package structure  131  may comprise at least two discrete antennas  102 ,  102 ′. An advantage of forming/coupling the device  118  and discrete antennas  102 ,  102 ′ in a partially embedded substrate  127  is an overall Z-height reduction of the package structure  131 . In another embodiment, the device  118  and antennas  102 ,  102 ′ may be fully embedded in the substrate  127 . 
       FIG. 1 c    depicts an embodiment wherein a package structure  132  comprises two devices  118 ,  118 ′ (similar to the device  118  and associated package  100  components of  FIG. 1 a   ) stacked upon one another. The first device/die  118  may be coupled with/disposed on the package substrate  126 , which may comprise any type of suitable package substrate  126 , and the second device/die  118 ′ may be disposed/stacked on the first device  118 . The first device  118  may be coupled with the second device  118 ′ by ground vias  117 ′ and signal vias  116 ′, as well as by ground interconnect structures  123  and signal interconnect structures  125 . In an embodiment, the discrete antenna  102  (similar to the discrete antenna of  FIG. 1 a   ), may comprise a dimension as small as 1 mm in width and 1 mm in length, and may be stacked on the first device  118  adjacent the second device  118 ′. In general, the dimensions of the discrete antenna of the embodiments comprise a fraction of the minimum wavelength in the frequency range of a particular application/design. 
     In an embodiment, the package structure  132  may comprise a system on chip including at least one 3D stacked millimeter wave chip antenna. In some embodiments, a plurality of discrete antennas may be placed/coupled with a backside of the first device  118 . In an embodiment, an optional radio frequency interference (RFI) shield  130  may be disposed around/may surround the stacked devices  118 ,  118 ′. In some embodiments, the RFI shield may be used to further isolate the discrete antenna (s) from the rest of the package structure components. 
     The embodiments herein include enablement of 3D integration of discrete antenna with package structures, wherein one or multiple discrete millimeter wave chip antennas are assembled on top of a main system on chip/CPU die/device, wherein the device comprises an integrated mm-wave radio. The antennas may be implemented on high performance millimeter wave substrates, such as glass for example, wherein the millimeter wave signal may be coupled between the discrete antenna and the device using through substrate vias. The embodiments herein support integration of the 3D discrete antennas into such applications as ultra-short range chip-to-chip communication and post silicon validation of SoC/CPU chips using a wireless debug port, for example. Applications such as wireless signal to logic analyzer, and wireless multiple antenna transmission between devices, such as between mobile devices and/or between such devices as DVD and display devices, for example, are enabled herein. 
     In another embodiment, a method of forming a package structure is depicted in  FIG. 2 . At step  202 , at least one discrete antenna is formed on a back side of a device, wherein the discrete antenna comprises an antenna substrate. At step  204 , a through antenna substrate via is formed through the antenna substrate, wherein the through the through antenna substrate via is vertically disposed through the antenna substrate. At step  206 , the through antenna substrate via is coupled with a through substrate via that is vertically disposed within the device, and At step  208 , the device is coupled with a package substrate. 
     Turning now to  FIG. 3 , illustrated is an embodiment of a computing system  300 . The system  300  includes a number of components disposed on a mainboard  310  or other circuit board. Mainboard  310  includes a first side  312  and an opposing second side  314 , and various components may be disposed on either one or both of the first and second sides  312 ,  314 . In the illustrated embodiment, the computing system  300  includes a package structure  340  (which may be similar to the package structure  100  of  FIG. 1 a   , for example) disposed on the mainboard&#39;s first side  312 , wherein the package structure  340  may comprise any of the microchannel structure embodiments described herein. 
     System  300  may comprise any type of computing system, such as, for example, a hand-held or mobile computing device (e.g., a cell phone, a smart phone, a mobile internet device, a music player, a tablet computer, a laptop computer, a nettop computer, etc.). However, the disclosed embodiments are not limited to hand-held and other mobile computing devices and these embodiments may find application in other types of computing systems, such as desk-top computers and servers. 
     Mainboard  310  may comprise any suitable type of circuit board or other substrate capable of providing electrical communication between one or more of the various components disposed on the board. In one embodiment, for example, the mainboard  310  comprises a printed circuit board (PCB) comprising multiple metal layers separated from one another by a layer of dielectric material and interconnected by electrically conductive vias. Any one or more of the metal layers may be formed in a desired circuit pattern to route—perhaps in conjunction with other metal layers—electrical signals between the components coupled with the board  310 . However, it should be understood that the disclosed embodiments are not limited to the above-described PCB and, further, that mainboard  310  may comprise any other suitable substrate. 
     In addition to the package structure  340 , one or more additional components may be disposed on either one or both sides  312 ,  314  of the mainboard  310 . By way of example, as shown in the figures, components  301   a  may be disposed on the first side  312  of the mainboard  310 , and components  301   b  may be disposed on the mainboard&#39;s opposing side  314 . Additional components that may be disposed on the mainboard  310  include other IC devices (e.g., processing devices, memory devices, signal processing devices, wireless communication devices, graphics controllers and/or drivers, audio processors and/or controllers, etc.), power delivery components (e.g., a voltage regulator and/or other power management devices, a power supply such as a battery, and/or passive devices such as a capacitor), and one or more user interface devices (e.g., an audio input device, an audio output device, a keypad or other data entry device such as a touch screen display, and/or a graphics display, etc.), as well as any combination of these and/or other devices. 
     In one embodiment, the computing system  300  includes a radiation shield. In a further embodiment, the computing system  300  includes a cooling solution. In yet another embodiment, the computing system  300  includes an antenna. In yet a further embodiment, the assembly  300  may be disposed within a housing or case. Where the mainboard  310  is disposed within a housing, some of the components of computer system  300 —e.g., a user interface device, such as a display or keypad, and/or a power supply, such as a battery—may be electrically coupled with the mainboard  310  (and/or a component disposed on this board) but may be mechanically coupled with the housing. 
       FIG. 4  is a schematic of a computer system  400  according to an embodiment. The computer system  400  (also referred to as the electronic system  400 ) as depicted can embody/include a package structure that includes any of the several disclosed embodiments and their equivalents as set forth in this disclosure. The computer system  400  may be a mobile device such as a netbook computer. The computer system  400  may be a mobile device such as a wireless smart phone. The computer system  400  may be a desktop computer. The computer system  400  may be a hand-held reader. The computer system  400  may be integral to an automobile. The computer system  400  may be integral to a television. 
     In an embodiment, the electronic system  400  is a computer system that includes a system bus  420  to electrically couple the various components of the electronic system  400 . The system bus  420  is a single bus or any combination of busses according to various embodiments. The electronic system  400  includes a voltage source  430  that provides power to the integrated circuit  410 . In some embodiments, the voltage source  430  supplies current to the integrated circuit  410  through the system bus  420 . 
     The integrated circuit  410  is electrically, communicatively coupled to the system bus  420  and includes any circuit, or combination of circuits according to an embodiment, including the package/device of the various embodiments included herein. In an embodiment, the integrated circuit  410  includes a processor  412  that can include any type of packaging structures according to the embodiments herein. As used herein, the processor  412  may mean any type of circuit such as, but not limited to, a microprocessor, a microcontroller, a graphics processor, a digital signal processor, or another processor. In an embodiment, the processor  412  includes any of the embodiments of the package structures disclosed herein. In an embodiment, SRAM embodiments are found in memory caches of the processor. 
     Other types of circuits that can be included in the integrated circuit  410  are a custom circuit or an application-specific integrated circuit (ASIC), such as a communications circuit  414  for use in wireless devices such as cellular telephones, smart phones, pagers, portable computers, two-way radios, and similar electronic systems. In an embodiment, the processor  412  includes on-die memory  416  such as static random-access memory (SRAM). In an embodiment, the processor  412  includes embedded on-die memory  416  such as embedded dynamic random-access memory (eDRAM). 
     In an embodiment, the integrated circuit  410  is complemented with a subsequent integrated circuit  411 . In an embodiment, the dual integrated circuit  411  includes embedded on-die memory  417  such as eDRAM. The dual integrated circuit  411  includes an RFIC dual processor  413  and a dual communications circuit  415  and dual on-die memory  417  such as SRAM. The dual communications circuit  415  may be configured for RF processing. 
     At least one passive device  480  is coupled to the subsequent integrated circuit  411 . In an embodiment, the electronic system  400  also includes an external memory  440  that in turn may include one or more memory elements suitable to the particular application, such as a main memory  442  in the form of RAM, one or more hard drives  444 , and/or one or more drives that handle removable media  446 , such as diskettes, compact disks (CDs), digital variable disks (DVDs), flash memory drives, and other removable media known in the art. The external memory  440  may also be embedded memory  448 . In an embodiment, the electronic system  400  also includes a display device  450 , and an audio output  460 . In an embodiment, the electronic system  400  includes an input device such as a controller  470  that may be a keyboard, mouse, touch pad, keypad, trackball, game controller, microphone, voice-recognition device, or any other input device that inputs information into the electronic system  400 . In an embodiment, an input device  470  includes a camera. In an embodiment, an input device  470  includes a digital sound recorder. In an embodiment, an input device  470  includes a camera and a digital sound recorder. 
     Although the foregoing description has specified certain steps and materials that may be used in the methods of the embodiments, those skilled in the art will appreciate that many modifications and substitutions may be made. Accordingly, it is intended that all such modifications, alterations, substitutions and additions be considered to fall within the spirit and scope of the embodiments as defined by the appended claims. In addition, the Figures provided herein illustrate only portions of exemplary microelectronic devices and associated package structures that pertain to the practice of the embodiments. Thus the embodiments are not limited to the structures described herein.