Embodiments of the present disclosure generally relate to the field of package assemblies, and in particular package assemblies that include power domains.
Continued reduction in end product size of mobile electronic devices such as smart phones and ultrabooks is a driving force for the development of reduced size system in package components. In particular, reducing the Z-height of semiconductor packages.
Embodiments of the present disclosure may generally relate to systems, apparatus, and/or processes directed to creating an electrical conductor, or power corridor, on the outside of a package substrate, wherein the electrical conductor is raised, or extends from a surface of the package substrate. In embodiments, this electrical conductor may be used to reduce the number of layers required within the package substrate by removing power planes within the substrate to the electrical conductors on the surface of the package. In embodiments, there may be more than one electrical conductor on a surface of a package substrate, for example to route different power domains.
In embodiments, the electrical conductor, which may also be referred to as a power corridor, a power rail, a power plane, an external power plane, or an electrical bus, a power net, may be formed on a surface of a substrate using, for example metal deposition techniques. In embodiments, the electrical conductor may be pre-formed, and applied to a surface of the substrate. These embodiments may be used to provide extra stiffening for the package substrate, particular for thin substrates, or substrates that have no core or a very thin core. In embodiments, the core may include glass, ceramic, photo definable glass, or copper clad laminate (CCL). In nonlimiting embodiments, the glass core may have a thickness ranging from 40 μm 250 μm.
In embodiments, the electrical conductor may be formed or placed by a surface of a substrate that includes one or more electrical connections. In particular, the electrical conductor may be placed on the bottom surface of the substrate that couples with a PCB using a ball grid array (BGA). In embodiments, the electrical conductor may have a thickness above the surface of the substrate that allows portions of the electrical conductor to fit between individual balls of the BGA, and does not interfere with the coupling of the substrate with the BGA. In particular, the thickness of the electrical conductor may be the same or less than a distance between the surface of the substrate and the surface of the PCB. In embodiments, this thickness may be substantially thicker than the thickness of legacy traces or routings at the surface of the substrate.
In embodiments, using the electrical conductor as described herein may be used to reduce package layer counts, which may decrease costs and also address anticipated supply-chain constraints in the near and long-term. Reducing package layer counts also reduces the overall Z-height of the package. In embodiments, reducing the number of layers in the package involves removing layers that may be used for power delivery, ground planes, or power planes, in legacy packages. However, simply removing these power planes risks load line deterioration of the power delivery network by 1 to several milliohms. This is addressed, in embodiments described herein, by elevating traces above a package surface to improve a power delivery load line. In embodiments, these elevated traces, or electrical conductors, may be used on the package substrate surface to improve power delivery performance. The power delivery performance may be improved by reducing the equivalent series resistance (ESR) of the power delivery network. Routing power delivery on a side, or outside, the die shadow allows smaller ESR values by thickening the trace on the surface.
In the following detailed description, reference is made to the accompanying drawings which form a part hereof, wherein like numerals designate like parts throughout, and in which is shown by way of illustration embodiments in which the subject matter of the present disclosure may be practiced. It is to be understood that other embodiments may be utilized and structural or logical changes may be made without departing from the scope of the present disclosure. Therefore, the following detailed description is not to be taken in a limiting sense, and the scope of embodiments is defined by the appended claims and their equivalents.
For the purposes of the present disclosure, the phrase “A and/or B” means (A), (B), or (A and B). For the purposes of the present disclosure, the phrase “A, B, and/or C” means (A), (B), (C), (A and B), (A and C), (B and C), or (A, B and C).
The description may use perspective-based descriptions such as top/bottom, in/out, over/under, and the like. Such descriptions are merely used to facilitate the discussion and are not intended to restrict the application of embodiments described herein to any particular orientation.
The description may use the phrases “in an embodiment,” or “in embodiments,” which may each refer to one or more of the same or different embodiments. Furthermore, the terms “comprising,” “including,” “having,” and the like, as used with respect to embodiments of the present disclosure, are synonymous.
The term “coupled with,” along with its derivatives, may be used herein. “Coupled” may mean one or more of the following. “Coupled” may mean that two or more elements are in direct physical or electrical contact. However, “coupled” may also mean that two or more elements indirectly contact each other, but yet still cooperate or interact with each other, and may mean that one or more other elements are coupled or connected between the elements that are said to be coupled with each other. The term “directly coupled” may mean that two or more elements are in direct contact.
Various operations may be described as multiple discrete operations in turn, in a manner that is most helpful in understanding the claimed subject matter. However, the order of description should not be construed as to imply that these operations are necessarily order dependent.
As used herein, the term “module” may refer to, be part of, or include an ASIC, an electronic circuit, a processor (shared, dedicated, or group) and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable components that provide the described functionality.
Various Figures herein may depict one or more layers of one or more package assemblies. The layers depicted herein are depicted as examples of relative positions of the layers of the different package assemblies. The layers are depicted for the purposes of explanation, and are not drawn to scale. Therefore, comparative sizes of layers should not be assumed from the Figures, and sizes, thicknesses, or dimensions may be assumed for some embodiments only where specifically indicated or discussed.
The package substrate 104 may be physically and/or electrically coupled with a PCB 108 using a BGA 110 that includes a plurality of balls 110a. In implementations, there may be a solder resist layer 112 on top of the PCB 108 that may surround the BGA 110. During operation, signals and/or power may be routed between the PCB 108 and the dies 102 using the BGA 110, the package substrate 104, and the die connectors 106.
In legacy implementations, the package substrate 104 may include multiple layers. For example, a core 104a may be used to provide rigidity or certain thermal characteristics to the package substrate 104. The core may also be used to embed components such as inductors, capacitors required for the operation of the die 102. In addition, various routing layers 104b may be used to route signals, power, or ground. Legacy package substrate 104 also includes power planes 104c that may be dedicated to power delivery. In implementations, multiple power planes 104c may be used to provide separate power domains, for example 1.3V and 1.1V switching voltages that may be used by separate dies 102. Separate power domains may be dedicated to different circuits, for example a graphics circuit may require a different power domain than the CPU core or a memory physical layer. Dielectric layers 104d may provide separation for the routing layers 104b and power planes 104c. In implementations, vias (not shown) may provide electrical connections between the various layers.
In implementations, a top layer 104f may include traces (not shown) to electrically couple the package substrate 104 with the die connector 106. A bottom layer 104e may include a plurality of contacts 114 to electrically couple with the BGA 110. In implementations, routings 116 may be used as ground reference (VSS) for signals and power through package substrate 104. In these legacy implementations, there may be a distance “w” 118 between the bottom layer 104e of the substrate package 104 and the top of the PCB 108, which may include the top of the solder resist layer 112, between the individual balls 110a of the BGA 110. Diagram 150 shows a top-down view of legacy system 100.
The package substrate 204 may then be physically and electrically coupled with the PCB 208 using BGA 210, which may be similar to PCB 108 and BGA 110 of
The package substrate 204 may include a core 204a, routing layers 204b, and dielectric layers 204d, which may be similar to core 104a, routing layers 104b, and dielectric layers 104d of
As shown in this embodiment, some of the dedicated power planes, for example the power planes 104c of
In embodiments, the electrical conductors 220 may be referred to as power corridors, power planes, power rails, power nets, or electrical buses. In embodiments, the electrical conductors 220 may include copper, or may include some other electrically conductive material such as gold or aluminum. In embodiments, a thickness of the electrical conductors 220 may range from 30 μm to 150 μm, which may facilitate power delivery. This may be substantially thicker than a thickness of the plurality of contacts 214 that may be used for signaling, including high-speed and control signaling. In embodiments, a thickness of a contact 215 that is electrically coupled with the electrical routing 208a may be different than a thickness of the plurality of contacts 214, for example if power to the electrical conductors 220 from the PCB 208 flows through the contact 215. In other embodiments, thicknesses may be the same. In embodiments, the overall cross-section may define the current carrying capability.
In embodiments, the electrical conductors 220 may be applied to the package substrate 204 using a metal deposition technique, such as direct plating or cold spray. In embodiments, electroplating may involve creating a seed layer within the substrate, wherein the substrate is submerged in a copper-based solution. An electrochemical process then enables the migration of copper particles from the solution to the seed layer. Growing fixed copper using the electroplating process may be a lengthy process. In embodiments, a solution may then be used that contains copper nanoparticles. The solution is sprayed on the substrate, for example at room temperature, to form an electrical conductor on the substrate. The cold spray process may be used to create thick copper layers in a relatively short time. In embodiments, different types of metals and nonmetals, such as diamond, may be used in the cold spray process.
In other embodiments, the electrical conductors 220 may be pre-formed and attached to the package substrate 204 during the assembly process. In embodiments, the electrical conductors 220 may have a uniform thickness, or may have a variable thickness that may depend on the routing and constraints in the SLI BGA 210 during operation. In embodiments, plated or filled vias (not shown), in addition to power routings (not shown) may be used to bring power from the electrical conductors 220 into the package substrate 204. In addition, the electrical conductors 220 may be coupled with one or more balls of the BGA 210 to route power between the one or more balls, as discussed further below.
In embodiments, the electrical conductors 220 may be a single electrical conductor that routes a single power domain. In other embodiments, the electrical conductors 220 may include multiple conductors that are electrically isolated from each other, where each may be associated with a different power domain. In some embodiments, a non-electrically conductive protective layer such as epoxy, solder mask, silicon nitride, silicon dioxide may be used surrounding a portion of the electrical conductor 220, for example to prevent corrosion or prevent an unintentional electrical short.
As discussed above with respect to
In embodiments, a first electrical conductor 420a, which may be similar to electrical conductor 220 of
Note that in embodiments (not shown), power may be received from an electrical conductor such as sixth electrical conductor 446b by metal vias (not shown) that extend within a substrate, such as substrate 204 of
A die side electrical conductor 560, which may be similar to electrical conductor 220 of
In embodiments, the vertical electrical coupling 570 may include various conductive components. For example, the vertical electrical coupling 570 may include upper vias 572, through holes 574, and lower vias 576 that are electrically coupled. In embodiments, the upper vias 572, through holes 574, and lower vias 576 may be plated or filled with an electrically conductive metal or with some other electrically conductive substance. In embodiments, the conductive components within the vertical electrical coupling 570 may be formed using techniques known in the art. In particular, through holes 574 may extend through a core 504a of the package substrate 504, which may be similar to core 204a of
In embodiments, the die side electrical conductor 560 may be electrically coupled with the die connectors 506 using electrical routings that may be found in the top layer 504f of the package substrate 504, which may be similar to top layer 204f of
In embodiments, a geometry including a thickness of the die side electrical conductor 560 may be selected based upon a power profile for the dies 502 during operation of the system 500. In addition, a size of the vertical electrical coupling 570, as well as a number of vertical electrical coupling 570 to electrically couple with the die side electrical conductor 560 may also be based on the power profile. It should be appreciated that although
At block 602, the process may include providing a substrate, wherein the substrate has a first side and a second side opposite the first side, and wherein the first side of the substrate includes a plurality of electrical contacts. In embodiments, the substrate may be similar to package substrate 104 of
At block 604, the process may further include forming an electrical bus on the first side of the substrate, wherein the electrical bus has a thickness that extends from a surface of the first side of the substrate, and wherein the electrical bus is not directly electrically coupled to at least some of the plurality of electrical contacts. In embodiments, the electrical bus may be similar to electrical conductors 220 of
In an embodiment, the electronic system 700 is a computer system that includes a system bus 720 to electrically couple the various components of the electronic system 700. The system bus 720 is a single bus or any combination of busses according to various embodiments. The electronic system 700 includes a voltage source 730 that provides power to the integrated circuit 710. In some embodiments, the voltage source 730 supplies current to the integrated circuit 710 through the system bus 720.
The integrated circuit 710 is electrically coupled to the system bus 720 and includes any circuit, or combination of circuits according to an embodiment. In an embodiment, the integrated circuit 710 includes a processor 712 that can be of any type. As used herein, the processor 712 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 712 includes, or is coupled with, an electrical conductor extending from a surface of a 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 710 are a custom circuit or an application-specific integrated circuit (ASIC), such as a communications circuit 714 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 710 includes on-die memory 716 such as static random-access memory (SRAM). In an embodiment, the integrated circuit 710 includes embedded on-die memory 716 such as embedded dynamic random-access memory (eDRAM).
In an embodiment, the integrated circuit 710 is complemented with a subsequent integrated circuit 711. Useful embodiments include a dual processor 713 and a dual communications circuit 715 and dual on-die memory 717 such as SRAM. In an embodiment, the dual integrated circuit 710 includes embedded on-die memory 717 such as eDRAM.
In an embodiment, the electronic system 700 also includes an external memory 740 that in turn may include one or more memory elements suitable to the particular application, such as a main memory 742 in the form of RAM, one or more hard drives 744, and/or one or more drives that handle removable media 746, such as diskettes, compact disks (CDs), digital variable disks (DVDs), flash memory drives, and other removable media known in the art. The external memory 740 may also be embedded memory 748 such as the first die in a die stack, according to an embodiment.
In an embodiment, the electronic system 700 also includes a display device 750, an audio output 760. In an embodiment, the electronic system 700 includes an input device such as a controller 770 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 700. In an embodiment, an input device 770 is a camera. In an embodiment, an input device 770 is a digital sound recorder. In an embodiment, an input device 770 is a camera and a digital sound recorder.
As shown herein, the integrated circuit 710 can be implemented in a number of different embodiments, including a package substrate having an electrical conductor extending from a surface of a 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 package substrate having an electrical conductor extending from a surface of a 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 an electrical conductor extending from a surface of a substrate embodiments and their equivalents. A foundation substrate may be included, as represented by the dashed line of
The following paragraphs describe examples of various embodiments.
Example 1 is an apparatus comprising: a substrate with a first side and a second side opposite the first side; a plurality of electrical contacts on the first side of the substrate; and an electrical conductor on the first side of the substrate and extending from a surface of the first side of the substrate, the electrical conductor electrically coupled with at least one of the plurality of electrical contacts.
Example 2 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor is electrically isolated from another one of the plurality of electrical contacts.
Example 3 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor has a thickness ranging from 30 μm to 150 μm.
Example 4 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor includes copper.
Example 5 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor further includes a protective layer surrounding at least a portion of the electrical conductor.
Example 6 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor forms a plane that surrounds at least one of the plurality of electrical contacts, and wherein the electrical conductor is electrically isolated from the at least one of the plurality of electrical contacts.
Example 7 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor is a first electrical conductor, and wherein the at least one of the plurality of electrical contacts is a first of the at least one of the plurality of electrical contacts; and further comprising: a second electrical conductor on the first side of the substrate, wherein the second electrical conductor is electrically isolated from the first electrical conductor; and wherein the second electrical conductor is electrically coupled with a second of the at least one of the plurality of electrical contacts.
Example 8 includes the apparatus of example 7, or of any other example or embodiment herein, wherein the first electrical conductor is associated with a first power domain, and the second electrical conductor is associated with a second power domain.
Example 9 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the electrical conductor has a uniform thickness.
Example 10 includes the apparatus of example 1, or of any other example or embodiment herein, wherein the first side of the substrate is coupled with a printed circuit board (PCB), wherein the plurality of contacts are coupled with the PCB using a ball grid array (BGA), and wherein the electrical conductor is electrically coupled with a first solder ball of the BGA and is electrically isolated from a second solder ball of the BGA.
Example 11 includes the apparatus of example 10, or of any other example or embodiment herein, wherein the first solder ball is associated with a power domain.
Example 12 includes the apparatus of example 1, or of any other example or embodiment herein, further comprising a die coupled with the first side of the substrate, wherein the die is electrically coupled with the electrical conductor, and wherein the electrical conductor is electrically coupled with the second side of the substrate through electrical pathways in the substrate.
Example 13 includes the apparatus of example 1, or of any other example or embodiment herein, wherein a thickness of the electrical conductor is greater than a thickness of another trace on the substrate.
Example 14 is a system comprising: a package that includes: a substrate with a first side and a second side opposite the first side; a plurality of electrical contacts on the first side of the substrate; and a power rail on the first side of the substrate, the power rail with a thickness that extends from the first side of the substrate, and wherein the power rail is not in direct electrical contact with at least some of the plurality of electrical contacts; and a board coupled with the first side of the substrate, wherein the power rail is not in direct physical contact with the board.
Example 15 includes the system of example 14, or of any other example or embodiment herein, further comprising a ball grid array (BGA) between the board and the first side of the substrate, wherein the power rail is in direct electrical contact with a first ball and with a second ball of the BGA.
Example 16 includes the system of example 15, or of any other example or embodiment herein, wherein the first ball is directly electrically coupled with the board, and wherein the second ball is not directly electrically coupled with the board.
Example 17 includes the system of example 14, or of any other example or embodiment herein, wherein the board is a printed circuit board (PCB).
Example 18 includes a system of example 14, or of any other example or embodiment herein, further comprising an electrical component coupled with the second side of the substrate, wherein the electrical component is electrically coupled with the power rail.
Example 19 includes the system of example 18, or of any other example or embodiment herein, wherein the electrical component includes a die.
Example 20 includes a system of example 18, or of any other example or embodiment herein, wherein the electrical component is a plurality of electrical components.
Example 21 is a method comprising: providing a substrate, wherein the substrate has a first side and a second side opposite the first side, and wherein the first side of the substrate includes a plurality of electrical contacts; and forming an electrical bus on the first side of the substrate, wherein the electrical bus has a thickness that extends from a surface of the first side of the substrate, and wherein the electrical bus is not directly electrically coupled to at least some of the plurality of electrical contacts.
Example 22 includes the method of example 21, or of any other example or embodiment herein, further comprising: coupling the first side of the substrate to a printed circuit board (PCB), wherein the coupling includes coupling a ball grid array (BGA) to the plurality of electrical contacts and coupling the BGA to the PCB.
Example 23 includes the method of example 22, or of any other example or embodiment herein, wherein the plurality of electrical contacts is a first plurality of electrical contacts; and wherein forming the electrical bus further includes electrically coupling a second plurality of electrical contacts.
Example 24 includes the method of example 21, or of any other example or embodiment herein, wherein the electrical bus is a first electrical bus; and further comprising: forming a second electrical bus on the second side of the substrate; and electrically coupling the first electrical bus and the second electrical bus using an electrical connection within the substrate that extends from the first side of the substrate to the second side of the substrate.
Example 25 includes the method of example 21, or of any other example or embodiment herein, wherein forming the electrical bus further includes forming the electrical bus using a selected one of: direct plating or cold spray.
Various embodiments may include any suitable combination of the above-described embodiments including alternative (or) embodiments of embodiments that are described in conjunctive form (and) above (e.g., the “and” may be “and/or”). Furthermore, some embodiments may include one or more articles of manufacture (e.g., non-transitory computer-readable media) having instructions, stored thereon, that when executed result in actions of any of the above-described embodiments. Moreover, some embodiments may include apparatuses or systems having any suitable means for carrying out the various operations of the above-described embodiments.
The above description of illustrated embodiments, including what is described in the Abstract, is not intended to be exhaustive or to limit embodiments to the precise forms disclosed. While specific embodiments are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the embodiments, as those skilled in the relevant art will recognize.
These modifications may be made to the embodiments in light of the above detailed description. The terms used in the following claims should not be construed to limit the embodiments to the specific implementations disclosed in the specification and the claims. Rather, the scope of the invention is to be determined entirely by the following claims, which are to be construed in accordance with established doctrines of claim interpretation.