Patent ID: 12191225

The use of the same reference symbols in different drawings indicates similar or identical items.

DETAILED DESCRIPTION OF DRAWINGS

The following description in combination with the Figures is provided to assist in understanding the teachings disclosed herein. The following discussion will focus on specific implementations and embodiments of the teachings. This focus is provided to assist in describing the teachings, and should not be interpreted as a limitation on the scope or applicability of the teachings. However, other teachings can certainly be used in this application. The teachings can also be used in other applications, and with several different types of architectures, such as distributed computing architectures, client/server architectures, or middleware server architectures and associated resources.

FIG.1illustrates a sectional view of an information handling system100in accordance with the prior art.FIG.1is provided for illustrative purposes and should not be understood to provide a scaled illustration. Information handling system100represents an electronic device that is designed to provide a low profile, compact design, such as a laptop computer, a tablet device, a cellular device, or other compact electronic device. Information handling system100includes a keyboard110, bottom side components130, a printed circuit board (PCB)140, a ball grid array (BGA) device150, a cold plate160, a heat pipe170, and a cover180. Keyboard110and cover180make up an enclosure for housing the components of information handling system100. It will be understood that, as used herein, the terms “top” and “bottom” are provided in relation to the current figures, and that, in a typical information handling system, the keyboard will likely be arranged on a different surface than illustrated herein.

PCB140is affixed between keyboard110and cover180, and the components of information handling system100are affixed to the PCB by, for example, a surface mount assembly process. In particular, on a bottom surface of PCB140, various bottom side components130are affixed. Information handling system100will be understood to be designed with the intent to permit cooling air to flow around bottom side components130, and that thus the information handling system will be in conformance with a specified minimum air gap190between the tallest component of the bottom side components and keyboard110.

BGA device150represents an integrated circuit device that is packaged in a conventional package, and may represent a central processing unit (CPU), a graphics processor, an I/O hub, or another highly integrated device, as needed or desired. BGA device150includes a device die that is fabricated to provide the functions and features of the BGA device, and that is affixed to a top surface of a substrate via electrical contact bumps, bond wires, or the like. The substrate is fabricated of patterned layers of metal sandwiched between layer of an insulating material. The patterned metal layers are interconnected with vias to provide circuit paths between the electrical contact bumps of the device die and a ball grid array (BGA) of solder contact pads on the bottom side of the substrate which includes solder balls that get soldered to patterned contacts on a top metallization layer of PCB140.

As illustrated, BGA device150includes capacitors, resistors, or other discrete components that are soldered to the bottom side of the substrate. BGA device150is characterized by the fact that the device die generates a large amount of heat when in operation that needs to be dissipated from the device die. As such, cold plate160is thermally attached to the top surface of the die of BGA device150, and heat pipe170is thermally attached to the top surface of the cold plate. Information handling system100will be understood to be designed with the intent to permit cooling air to flow around cold plate160, heat pipe170, and the components affixed to the top surface of PCB140, and that thus the information handling system will be in conformance with a specified minimum air gap195between the heat pipe170and cover180. As such, it will be understood that there is a minimum distance between the top of keyboard110and the bottom of cover180. Table 1 provides an example of the stack up distances and the minimum distance.

TABLE 1Stack Up DistancesComponentsStack Up HeightHeat Pipe to Cover0.5 mmHeat Pipe1.2 mmCold Plate0.5 mmBGA device1.2 mmPCB1.2 mmBottom Side Components1.0 mmBottom Side Components to Keyboard0.5 mmTotal6.1 mm

BGA device150is illustrated with the depth expanded to illustrate the circuit paths between the contact bumps on the bottom side of the device die and the contact pads on the bottom side of the substrate. Thus BGA device150necessitates that all of the circuit paths transit through all of the internal layers of the substrate. Such a routing scheme drives up the substrate layer count and increases the overall cost of the prior art BGA device. Further, the overall thickness the information handling system of the prior art is difficult to reduce, because reductions in any of the dimensions is difficult to achieve without limiting the performance or functionality of the other components.

For example, decreasing air gaps190and195may result in decreased system performance due to overheating of the components of information handling system100, and may make the exterior surfaces of keyboard110and cover180uncomfortably hot for the user of the information handling system. Further, reducing the layer count of PCB140may achieve an overall thinner structure, but such a reduction is typically done by reducing the number of metallization layers in the PCB which reduces the number of circuit paths that can be achieved, and hence leads to a reduction in the functionality of information handling system100. Moreover, reducing the depth of either cold plate160or heat pipe170typically results in higher operating temperatures of the device die of BGA device150, leading to decreased system performance of information handling system100.

FIG.2illustrates a sectional view of an information handling system200in accordance with an embodiment of the current disclosure.FIG.2is provided for illustrative purposes and should not be understood to provide a scaled illustration. Information handling system200is similar to information handling system100, and includes a keyboard210, a backplate220, bottom side components230, a PCB240, a BGA device250, a cold plate260, a heat pipe270, and a cover280. Keyboard210and cover280make up an enclosure for housing the components of information handling system200. PCB240is affixed between keyboard210and cover280, and the components of information handling system200are affixed to the PCB by, for example, a surface mount assembly process. In particular, on a bottom surface of PCB240, various bottom side components230are affixed. Information handling system200will be understood to be designed with the intent to permit cooling air to flow around bottom side components230, and that thus the information handling system will be in conformance with a specified minimum air gap290between the tallest component of the bottom side components and keyboard210.

BGA device250is similar to BGA device150, and includes a device die that is fabricated to provide the functions and features of the BGA device, and that is affixed to a top surface of a substrate via electrical contact bumps. The substrate is fabricated of patterned layers of metal sandwiched between layers of an insulating material. The patterned metal layers are interconnected with vias to provide circuit paths between the electrical contact bumps of the device die and a ball grid array (BGA) of solder contact pads. However, here, the BGA is on the top side of the substrate which includes solder balls that soldered to patterned contacts on the bottom metallization layer of PCB240, and the PCB is fabricated with a cutout area245that accommodates the device die within the cutout area. As illustrated, BGA device250includes capacitors, resistors, or other discrete components soldered to the bottom side of the substrate.

BGA device250is characterized by the fact that the device die generates a large amount of heat when in operation that needs to be dissipated from the device die. As such, cold plate260is thermally attached to the top surface of the die of BGA device250, and heat pipe270is thermally attached to the top surface of the cold plate. Information handling system200will be understood to be designed with the intent to permit cooling air to flow around cold plate260, heat pipe270, and the components affixed to the top surface of PCB240, and that thus the information handling system will be in conformance with a specified minimum air gap295between the heat pipe270and cover280. However, here, cold plate260is fabricated in such a way that the bottom surface of the cold plate goes through cutout area245from the top side of the PCB to come into thermal contact with the top side of the device die of BGA device250.

As such, there is a minimum distance between the top of keyboard210and the bottom of cover280. Here, because BGA device250is affixed to the bottom surface of PCB140and cold plate260extends through cutout area245to come into thermal contact with the top surface of the device die of the BGA device, the overall stack up is reduced by “hiding” the depth of the BGA device and the cold plate and a portion of the cold plate within the depth of the PCB. Backplate220operates to provide mechanical stability to the assembly of information handling system200. For example, note that in information handling system100, compression from cold plate160acts to compress BGA device150into PCB140, while in information handling system200, the compression from cold plate260places BGA device250in tension on the bottom side of PCB240.

As such, backplate220may include mechanical retainers that permit the backplate to compress BGA device250into the bottom side of PCB240, thereby eliminating the tension on the solder connections between the BGA device and the PCB. Here, backplate220may be in contact with keyboard210, as needed or desired, however this is not necessarily so, and the backplate may have a thinner depth, or may be affixed to a keyboard support element, not illustrated. Table 2 provides an example of the stack up distances and the minimum distance.

TABLE 2Stack Up DistancesComponentsStack Up HeightHeat Pipe to Cover0.5 mmHeat Pipe1.2 mmCold Plate0.5 mmPCB1.2 mmBottom Side Components1.0 mmBottom Side Components to Keyboard0.5 mmTotal4.9 mm

BGA device250is illustrated with the depth expanded to illustrate the circuit paths256between the contact bumps252on the bottom side of the device die251and the contact pads254(i.e., the ball grid array) on the top side of the substrate253. Thus BGA device250does not require that all of the circuit paths transit through all of the internal layers of the substrate253. As such, it may be possible to reduce the substrate layer count, including a decrease in the number of metallization layers255, and to decrease the overall cost of BGA device250as compared with BGA device150. BGA device250includes other elements258, such as capacitors, resistors, or the like, on the bottom surface of the substrate253.

FIG.3illustrates a generalized embodiment of an information handling system300. For purpose of this disclosure an information handling system can include any instrumentality or aggregate of instrumentalities operable to compute, classify, process, transmit, receive, retrieve, originate, switch, store, display, manifest, detect, record, reproduce, handle, or utilize any form of information, intelligence, or data for business, scientific, control, entertainment, or other purposes. For example, information handling system300can be a personal computer, a laptop computer, a smart phone, a tablet device or other consumer electronic device, a network server, a network storage device, a switch router or other network communication device, or any other suitable device and may vary in size, shape, performance, functionality, and price. Further, information handling system300can include processing resources for executing machine-executable code, such as a central processing unit (CPU), a programmable logic array (PLA), an embedded device such as a System-on-a-Chip (SoC), or other control logic hardware. Information handling system300can also include one or more computer-readable medium for storing machine-executable code, such as software or data. Additional components of information handling system300can include one or more storage devices that can store machine-executable code, one or more communications ports for communicating with external devices, and various input and output (I/O) devices, such as a keyboard, a mouse, and a video display. Information handling system300can also include one or more buses operable to transmit information between the various hardware components.

Information handling system300can include devices or modules that embody one or more of the devices or modules described below, and operates to perform one or more of the methods described below. Information handling system300includes a processors302and304, an input/output (I/O) interface310, memories320and325, a graphics interface330, a basic input and output system/universal extensible firmware interface (BIOS/UEFI) module340, a disk controller350, a hard disk drive (HDD)354, an optical disk drive (ODD)356, a disk emulator360connected to an external solid state drive (SSD)364, an I/O bridge370, one or more add-on resources374, a trusted platform module (TPM)376, a network interface380, and a management device390. Processors302and304, I/O interface310, memory320, graphics interface330, BIOS/UEFI module340, disk controller350, HDD354, ODD356, disk emulator360, SSD364, I/O bridge370, add-on resources374, TPM376, and network interface380operate together to provide a host environment of information handling system300that operates to provide the data processing functionality of the information handling system. The host environment operates to execute machine-executable code, including platform BIOS/UEFI code, device firmware, operating system code, applications, programs, and the like, to perform the data processing tasks associated with information handling system300.

In the host environment, processor302is connected to I/O interface310via processor interface306, and processor304is connected to the I/O interface via processor interface308. Memory320is connected to processor302via a memory interface322. Memory325is connected to processor304via a memory interface327. Graphics interface330is connected to I/O interface310via a graphics interface332, and provides a video display output337to a video display334. In a particular embodiment, information handling system300includes separate memories that are dedicated to each of processors302and304via separate memory interfaces. An example of memories320and325include random access memory (RAM) such as static RAM (SRAM), dynamic RAM (DRAM), non-volatile RAM (NV-RAM), or the like, read only memory (ROM), another type of memory, or a combination thereof.

BIOS/UEFI module340, disk controller350, and I/O bridge370are connected to I/O interface310via an I/O channel312. An example of I/O channel312includes a Peripheral Component Interconnect (PCI) interface, a PCI-Extended (PCI-X) interface, a high-speed PCI-Express (PCIe) interface, another industry standard or proprietary communication interface, or a combination thereof. I/O interface310can also include one or more other I/O interfaces, including an Industry Standard Architecture (ISA) interface, a Small Computer Serial Interface (SCSI) interface, an Inter-Integrated Circuit (I2C) interface, a System Packet Interface (SPI), a Universal Serial Bus (USB), another interface, or a combination thereof. BIOS/UEFI module340includes BIOS/UEFI code operable to detect resources within information handling system300, to provide drivers for the resources, initialize the resources, and access the resources. BIOS/UEFI module340includes code that operates to detect resources within information handling system300, to provide drivers for the resources, to initialize the resources, and to access the resources.

Disk controller350includes a disk interface352that connects the disk controller to HDD354, to ODD356, and to disk emulator360. An example of disk interface352includes an Integrated Drive Electronics (IDE) interface, an Advanced Technology Attachment (ATA) such as a parallel ATA (PATA) interface or a serial ATA (SATA) interface, a SCSI interface, a USB interface, a proprietary interface, or a combination thereof. Disk emulator360permits SSD364to be connected to information handling system300via an external interface362. An example of external interface362includes a USB interface, an IEEE 1394 (Firewire) interface, a proprietary interface, or a combination thereof. Alternatively, solid-state drive364can be disposed within information handling system300.

I/O bridge370includes a peripheral interface372that connects the I/O bridge to add-on resource374, to TPM376, and to network interface380. Peripheral interface372can be the same type of interface as I/O channel312, or can be a different type of interface. As such, I/O bridge370extends the capacity of I/O channel312when peripheral interface372and the I/O channel are of the same type, and the I/O bridge translates information from a format suitable to the I/O channel to a format suitable to the peripheral channel372when they are of a different type. Add-on resource374can include a data storage system, an additional graphics interface, a network interface card (NIC), a sound/video processing card, another add-on resource, or a combination thereof. Add-on resource374can be on a main circuit board, on separate circuit board or add-in card disposed within information handling system300, a device that is external to the information handling system, or a combination thereof.

Network interface380represents a NIC disposed within information handling system300, on a main circuit board of the information handling system, integrated onto another component such as I/O interface310, in another suitable location, or a combination thereof. Network interface device380includes network channels382and384that provide interfaces to devices that are external to information handling system300. In a particular embodiment, network channels382and384are of a different type than peripheral channel372and network interface380translates information from a format suitable to the peripheral channel to a format suitable to external devices. An example of network channels382and384includes InfiniBand channels, Fibre Channel channels, Gigabit Ethernet channels, proprietary channel architectures, or a combination thereof. Network channels382and384can be connected to external network resources (not illustrated). The network resource can include another information handling system, a data storage system, another network, a grid management system, another suitable resource, or a combination thereof.

Management device390represents one or more processing devices, such as a dedicated baseboard management controller (BMC) System-on-a-Chip (SoC) device, one or more associated memory devices, one or more network interface devices, a complex programmable logic device (CPLD), and the like, that operate together to provide the management environment for information handling system300. In particular, management device390is connected to various components of the host environment via various internal communication interfaces, such as a Low Pin Count (LPC) interface, an Inter-Integrated-Circuit (I2C) interface, a PCIe interface, or the like, to provide an out-of-band (00B) mechanism to retrieve information related to the operation of the host environment, to provide BIOS/UEFI or system firmware updates, to manage non-processing components of information handling system300, such as system cooling fans and power supplies. Management device390can include a network connection to an external management system, and the management device can communicate with the management system to report status information for information handling system300, to receive BIOS/UEFI or system firmware updates, or to perform other task for managing and controlling the operation of information handling system300. Management device390can operate off of a separate power plane from the components of the host environment so that the management device receives power to manage information handling system300when the information handling system is otherwise shut down. An example of management device390include a commercially available BMC product or other device that operates in accordance with an Intelligent Platform Management Initiative (IPMI) specification, a Web Services Management (WSMan) interface, a Redfish Application Programming Interface (API), another Distributed Management Task Force (DMTF), or other management standard, and can include an Integrated Dell Remote Access Controller (iDRAC), an Embedded Controller (EC), or the like. Management device390may further include associated memory devices, logic devices, security devices, or the like, as needed or desired.

Although only a few exemplary embodiments have been described in detail herein, those skilled in the art will readily appreciate that many modifications are possible in the exemplary embodiments without materially departing from the novel teachings and advantages of the embodiments of the present disclosure. Accordingly, all such modifications are intended to be included within the scope of the embodiments of the present disclosure as defined in the following claims. In the claims, means-plus-function clauses are intended to cover the structures described herein as performing the recited function and not only structural equivalents, but also equivalent structures.

The above-disclosed subject matter is to be considered illustrative, and not restrictive, and the appended claims are intended to cover any and all such modifications, enhancements, and other embodiments that fall within the scope of the present invention. Thus, to the maximum extent allowed by law, the scope of the present invention is to be determined by the broadest permissible interpretation of the following claims and their equivalents, and shall not be restricted or limited by the foregoing detailed description.