Embodiments are in the field of integrated circuit packages and, in particular, semiconductor packages including package substrates having embedded dies.
Non-volatile memory systems, such as flash memory devices, may include several memory dies controlled by a memory controller. For example, a flash memory controller may manage data stored in the memory dies of a memory stack. As the art of non-volatile memory solutions evolves, a form factor of the memory systems is expected to decrease. More particularly, to meet the requirements for mobile and ultra-mobile markets, a z-height and an x-y area of memory devices is expected to shrink.
Semiconductor packages including active package substrates are described. In the following description, numerous specific details are set forth, such as packaging and interconnect architectures, in order to provide a thorough understanding of embodiments of the present invention. It will be apparent to one skilled in the art that embodiments of the present invention may be practiced without these specific details. In other instances, well-known features, such as specific semiconductor fabrication processes, are not described in detail in order to not unnecessarily obscure embodiments of the present invention. Furthermore, it is to be understood that the various embodiments shown in the Figures are illustrative representations and are not necessarily drawn to scale.
Meeting the space constraints of next-generation memory solutions presents a challenge. In particular, as more dies are added to a memory stack, including more memory dies and/or memory controller dies, a z-height of the device may increase and z-height limitations may be exceeded. To remain within z-height constraints, dies may be spread out laterally, but doing so could increase a footprint of the device beyond customer needs. Dies may be embedded in a package substrate to utilize the substrate envelope, but a pitch size of the embedded die pads may be closely packed, leading to a mismatch and disconnects between the die pads and substrate signal routing, e.g., vias.
In an aspect, a memory system is miniaturized by embedding one or more dies within a substrate of the system. For example, an active die, such as a memory controller, may be embedded in a package substrate to utilize available vertical height of the substrate and minimize a z-height of the memory device. Furthermore, to avoid disconnects between substrate signal routing and die pads on the embedded die, the die may be mounted on an interposer. That is, the die and the interposer may be embedded, and the interposer may fan out signals from the closely packed die pads to more widely spaced vias. Memory dies may be connected to the vias. For example, interconnect wires of the memory dies may be attached to pads on the via. Thus, the active die may be reliably connected to memory dies mounted on the package substrate to meet advanced memory system application needs.
Referring to
In an embodiment, active package substrate 106 may be mounted on a circuit board 112. For example, semiconductor package 102 of semiconductor package assembly 100 may be ball grid array (BGA) component having several solder balls 114 arranged in a ball field. That is, an array of solder balls 114 may be arranged in a grid or other pattern. Each solder ball 114 may be mounted and attached to a corresponding contact pad 116 of circuit board 112. Circuit board 112 may be a motherboard or another printed circuit board of a computer system or device, e.g., a flash memory stick. Circuit board 112 may include signal routing to external device connectors (not shown). Accordingly, the solder ball and contact pad attachments may provide a physical and electrical interface between the dies of semiconductor package 102 and an external device.
Referring to
In an embodiment, active package substrate 106 includes an interposer 208. Interposer 208 may be embedded within any of the various layers of substrate laminate 108. For example, interposer 208 may be disposed within core layer 206. Interposer 208 may provide an electrical interface to fan out electrical signals from a first contact array 210 on a first side of interposer 208 to a second contact array 212 on a second side of interposer 208. More particularly, first contact array 210 may be on a mounting surface 214 of interposer 208 facing second substrate layer 204, and second contact array 212 may be on an interconnect surface 216 of interposer 208 facing first substrate layer 202. Each array may include several electrical contacts, and each contact of first contact array 210 may be electrically connected to a respective contact of second contact array 212 by one or more signal lines or vias (not shown). Thus, first contact array 210 may be electrically connected to second contact array 212.
Interposer 208 may be embedded within core layer 206. More particularly, core layer 206 may surround an interposer perimeter 218 of interposer 208. In an embodiment, an epoxy material of core layer 206 may be flowed around interposer 208 to surround interposer perimeter 218. Alternatively, a cavity may be formed in core layer 206, and interposer 208 may be mounted within the cavity. In either case, a portion of core layer 206 may cover interconnect surface 216 of interposer 208. Accordingly, core layer 206 may be disposed over second contact array 212 on interconnect surface 216 of interposer 208.
The embedded interposer 208 may fan out electrical signals from first contact array 210 to second contact array 212. For example, first contact array 210 may have a first array pitch, i.e., a distance between adjacent contacts, and second contact array 212 may have a second array pitch different than the first array pitch. In an embodiment, the first array pitch is smaller than the second array pitch. The contacts of first contact array 210 may be electrically connected to the contacts of second contact array 212 by one or more signal lines or vias passing through a thickness of interposer 208. Accordingly, interposer 208 may redistribute signals from a smaller and/or tighter pitch at first contact array 210 to a larger and/or wider pitch at second contact array 212.
An active die 220 may be embedded within substrate laminate 108 to communicate electrical signals to the contacts of interposer 208 for redistribution to memory dies 104 mounted on substrate laminate 108. More particularly, active die 220 may be mounted on mounting surface 214 of interposer 208 between first substrate layer 202 and second substrate layer 204 and may include several die pads 222 electrically connected to first contact array 210 of interposer 208. For example, die pads 222 of active die 220 may be bonded to contacts of interposer 208 using state-of-the-art flip chip techniques, e.g., mass reflow, thermal bonding, etc. One or more conductive pads 224 may be located between die pads 222 and first contact array 210, and conductive pads 224 may be reflowed to attach active die 220 to interposer 208. Alternatively, die pads 222 may be bonded to contacts of interposer 208 using a low temperature solder during a lamination process. Similarly, the bond between die pads 222 and contacts of interposer 208 may be formed by applying heat directly to die pads 222 and contacts of interposer 208, e.g., using resistive heating or similar techniques. In any case, active die 220 may be bonded to interposer 208 before or after embedding interposer 208 within substrate laminate 108.
Active die 220 may be embedded within any of the various layers of substrate laminate 108. For example, second substrate layer 204 may surround a die perimeter 226 of active die 220. In an embodiment, second substrate layer 204 may be flowed around active die 220. Alternatively, second substrate layer 204 may be laminated over active die 220 after active die 220 is mounted on interposer 208. In either case, second substrate layer 204 may cover both active die 220 and a portion of interposer 208. Accordingly, the assembly of interposer 208 and active die 220 may be sandwiched between second substrate layer 204 and first substrate layer 202.
Active die 220 may be a memory controller die, e.g., a flash memory controller. Thus, die pads 222 of active die 220 may communicate with memory dies 104 to read, write, and erase data to the non-volatile memory dies 104. That is, active die 220 may be a controller for managing the logic of a flash drive. In other embodiments, however, active die 220 may be a central processing unit, or another die type.
Die pads 222 of active die 220 may be placed in communication with electrical interconnects 110 of memory die 104 through one or more electrical interconnects. Substrate laminate 108 may include several vias 228 extending through first substrate layer 202. Vias 228 may electrically connect to contacts of second contact array 212. Electrical interconnects 110 of memory die 104 may be connected to vias 228. For example, wire interconnects of memory die 104 may be bonded or attached to pads on vias 228. Accordingly, electrical interconnects 110 of memory die 104 may be electrically connected to second contact array 212. That is, vias 228 may carry an electrical signal between the embedded interposer 208 and electrical interconnects 110 of memory die 104.
Certain advantages of the structure of package assembly having active package substrate 106 should now be apparent. For example, package assembly 100 having an embedded active die 220 may have a reduced z-height as compared to a similar package assembly having a memory controller located above the package substrate and within the memory stack. Furthermore, embedded interposer 208 can redistribute electrical signals from closely spaced die pads 222 of the embedded die 220 to more widely spaced vias connected to electrical interconnects 110 of memory dies 104. Thus, reliable electrical connections may be made between memory die 104 and the embedded active die 220. Certain advantages of such a structure will also become more apparent in the context of a manufacturing method used to build active package substrate 106, as described below.
Referring to
At operation 302, interposer 208 may be mounted within core layer 206. Referring to
When interposer 208 is embedded within core layer 206, interposer 208 may be simultaneously mounted over first substrate layer 202 of substrate laminate 108. That is, interconnect surface 216 may face first substrate layer 202 and be disposed above first substrate layer 202. A lower wall of core layer 206 may, however, separate interconnect surface 216 from first substrate layer 202. That is, the cavity within core layer 206 may not extend fully across the thickness of core layer 206, and thus, a thin wall of core layer 206 material may be sandwiched between interposer 208 and first substrate layer 202.
Interposer 208 may adhere to core layer 206. For example, interposer 208 may be pretreated to adhere to organic substrate materials, epoxy, prepreg, etc. When interposer 208 is formed from silicon, the silicon material may be roughened by a plasma etching process to enhance friction between interposer 208 and core layer 206. When interposer 208 is formed from an organic substrate material, the organic substrate material may be compatible with, e.g., may have a high coefficient of friction with, the epoxy or organic substrate used to form core layer 206. Accordingly, interposer 208 may be securely embedded within core layer 206.
Interposer 208 may fulfill functions other than signal redistribution. For example, interposer 208 may also redistribute heat from active die 220. That is, interposer 208 may transfer heat away from active die 220 during operation of semiconductor package 102 to maintain a temperature of active die 220 within operational temperature limits. In an embodiment, interposer 208 includes a heat pipe 402 extending from interconnect surface 216, e.g., from one or more contacts of second contact array 212, to mounting surface 214, e.g., to one or more contacts of first contact array 210. Heat pipe 402 may be formed from a heat conducting material, e.g., copper, deposited along a pathway between the opposite surfaces of interposer 208. Accordingly, heat generated by active die 220 may be transmitted from first contact array 210 through heat pipe 402 to second contact array 212. Furthermore, one or more interconnects, vias, or heat pipes may be connected to heat pipe 402 at second contact array 212 to transfer heat out of active package substrate 106. Accordingly, interposer 208 may reduce a likelihood of overheating.
Interposer 208 may also stabilize active package substrate 106. For example, interposer 208 may have a size and location within substrate laminate 108 to reduce warpage of the substrate laminate. In an embodiment, interposer 208 may be located such that variations in a coefficient of thermal expansion across substrate laminate 108 are minimized. Accordingly, when substrate laminate 108 is subjected to heat, e.g., during operation of active die 220, substrate laminate 108 is less likely to bend under varying thermally-induced mechanical stresses.
At operation 304, active die 220 may be mounted on mounting surface 214 of interposer 208. Referring to
Active die 220 may be mounted on interposer 208 using flip chip technologies. Accordingly, active die 220 may be bonded to interposer 208 before or after embedding within substrate laminate 108. For example, although the method is described as including attachment between active die 220 and interposer 208 after interposer 208 is embedded, active die 220 may be attached to interposer 208 and then the overall assembly may be embedded, e.g., during a substrate lamination process. Bonding may include copper reflow or other techniques. For example, die pads 222 may be bonded directly to contacts. In an embodiment, one or more conductive pads 224 may intervene between the die pads and contacts, and may facilitate bonding of die pads 222 to the contacts.
At operation 306, second substrate layer 204 may be formed over active die 220 to embed active die 220 and interposer 208 between first substrate layer 202 and second substrate layer 204. Referring to
At operation 308, electrical interconnects between the embedded die 220 and interposer 208 may be formed to facilitate electrical communication between the embedded components and external components. Still referring to
Referring to
Active package substrate 106 as shown in
In an embodiment, the electronic system 500 is a computer system that includes a system bus 520 to electrically couple the various components of the electronic system 500. The system bus 520 is a single bus or any combination of busses according to various embodiments. The electronic system 500 includes a voltage source 530 that provides power to the integrated circuit 510. In some embodiments, the voltage source 530 supplies current to the integrated circuit 510 through the system bus 520.
The integrated circuit 510 is electrically coupled to the system bus 520 and includes any circuit, or combination of circuits according to an embodiment. In an embodiment, the integrated circuit 510 includes a processor 512 that can be of any type. As used herein, the processor 512 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 512 includes, or is coupled with, a semiconductor package including an active package substrate, as 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 510 are a custom circuit or an application-specific integrated circuit (ASIC), such as a communications circuit 514 for use in wireless devices such as cellular telephones, smart phones, pagers, portable computers, two-way radios, and similar electronic systems, or a communications circuit for servers. In an embodiment, the integrated circuit 510 includes on-die memory 516 such as static random-access memory (SRAM). In an embodiment, the integrated circuit 510 includes embedded on-die memory 516 such as embedded dynamic random-access memory (eDRAM).
In an embodiment, the integrated circuit 510 is complemented with a subsequent integrated circuit 511. Useful embodiments include a dual processor 513 and a dual communications circuit 515 and dual on-die memory 517 such as SRAM. In an embodiment, the dual integrated circuit 511 includes embedded on-die memory 517 such as eDRAM.
In an embodiment, the electronic system 500 also includes an external memory 540 that in turn may include one or more memory elements suitable to the particular application, such as a main memory 542 in the form of RAM, one or more hard drives 544, and/or one or more drives that handle removable media 546, such as diskettes, compact disks (CDs), digital variable disks (DVDs), flash memory drives, and other removable media known in the art. The external memory 540 may also be embedded memory 548 such as the first die in a die stack, according to an embodiment.
In an embodiment, the electronic system 500 also includes a display device 550, and an audio output 560. In an embodiment, the electronic system 500 includes an input device such as a controller 570 that may be a keyboard, mouse, trackball, game controller, microphone, voice-recognition device, or any other input device that inputs information into the electronic system 500. In an embodiment, an input device 570 is a camera. In an embodiment, an input device 570 is a digital sound recorder. In an embodiment, an input device 570 is a camera and a digital sound recorder.
As shown herein, the integrated circuit 510 can be implemented in a number of different embodiments, including a semiconductor package including an active package substrate, according to any of the several disclosed embodiments and their equivalents, 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 a semiconductor package including an active package substrate, according to any of the several disclosed 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 I/O coupling requirements including array contact count, array contact configuration for a microelectronic die embedded in a processor mounting substrate according to any of the several disclosed package substrates having a semiconductor package including an active package substrate embodiments and their equivalents. A foundation substrate may be included, as represented by the dashed line of
Embodiments of a semiconductor package including an active package substrate are described above. In an embodiment, an active package substrate includes a substrate laminate including a core layer between a first substrate layer and a second substrate layer. The active package substrate include an interposer within the core layer. The interposer includes a first contact array on a mounting surface and a second contact array on an interconnect surface. The first contact array is electrically connected to the second contact array. The active package substrate includes an active die within the substrate laminate. The active die is mounted on the mounting surface of the interposer. The active die includes several die pads electrically connected to the first contact array.
In one embodiment, the substrate laminate includes several vias extending through the first substrate layer and electrically connected to the second contact array.
In one embodiment, a first array pitch of the first contact array is smaller than a second array pitch of the second contact array.
In one embodiment, the second substrate layer surrounds a die perimeter of the active die.
In one embodiment, the core layer surrounds an interposer perimeter of the interposer and covers the interconnect surface of the interposer.
In one embodiment, the active package substrate includes one or more conductive pads between the die pads and the first contact array.
In one embodiment, the interposer includes a heat pipe extending from the interconnect surface to the mounting surface.
In an embodiment, a semiconductor package includes an active package substrate including a substrate laminate including a core layer between a first substrate layer and a second substrate layer. The active package substrate includes an interposer within the core layer. The interposer includes a first contact array on a mounting surface and a second contact array on an interconnect surface. The first contact array is electrically connected to the second contact array. The active package substrate includes an active die within the substrate laminate. The active die is mounted on the mounting surface of the interposer. The active die includes several die pads electrically connected to the first contact array. The semiconductor package includes a memory die mounted on the substrate laminate. The memory die includes several electrical interconnects electrically connected to the second contact array.
In one embodiment, the substrate laminate includes several vias extending through the first substrate layer and electrically connected to the second contact array. The electrical interconnects are connected to the several vias.
In one embodiment, a first array pitch of the first contact array is smaller than a second array pitch of the second contact array.
In one embodiment, the second substrate layer surrounds a die perimeter of the active die.
In one embodiment, the core layer surrounds an interposer perimeter of the interposer and covers the interconnect surface of the interposer.
In one embodiment, the semiconductor package includes one or more conductive pads between the die pads and the first contact array.
In one embodiment, the interposer includes a heat pipe extending from the interconnect surface to the mounting surface.
In an embodiment, a method of embedding an active die and an interposer in an active package substrate includes mounting an interposer within a core layer and over a first substrate layer of a substrate laminate. The interposer includes a first contact array on a mounting surface and a second contact array on an interconnect surface facing the first substrate layer. The method includes mounting an active die on the mounting surface of the interposer. The active die includes several die pads electrically connected to the first contact array. The method includes forming a second substrate layer over the active die to embed the active die and the core layer between the first substrate layer and the second substrate layer of the substrate laminate.
In one embodiment, the method includes forming several vias in the first substrate layer and the core layer. The several vias are electrically connected to the second contact array of the interposer.
In one embodiment, a first array pitch of the first contact array is smaller than a second array pitch of the second contact array.
In one embodiment, the method includes mounting a memory die on the substrate laminate. The memory die includes several electrical interconnects electrically connected to several vias.
In one embodiment, the second substrate layer surrounds a die perimeter of the active die.
In one embodiment, the core layer surrounds an interposer perimeter of the interposer and covers the interconnect surface of the interposer.
Filing Document | Filing Date | Country | Kind |
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PCT/US2016/054958 | 9/30/2016 | WO | 00 |