Integrated circuits typically include various active and passive circuit elements which have been integrated into a piece of semiconductor material, often referred to as a die. One or more dies may, in turn, be encapsulated into a package 10 (
Referring now to the drawings in which like reference numbers represent corresponding parts throughout:
In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several embodiments of the present disclosure. It is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the present description.
As shown in
The printed circuit board 104 may be a single layer or multi-layered motherboard which has a plurality of conductors that provide communication between the circuits in the device 100 and other components mounted to the board 104. Alternatively, one or more of the CPU 52, memory 60 and controllers 62a, 62b . . . 62n may be disposed on other substrates such as daughter cards or expansion cards or any other substrate suitable for supporting a die, package or other substrate.
An operating system and various applications execute on the CPU 52 and reside in the memory 60. The content residing in memory 60 may be cached in accordance with appropriate caching techniques. Programs and data in memory 60 may be swapped into storage 64 (e.g., a non-volatile storage, such as magnetic disk drives, optical disk drives, a tape drive, etc.) as part of memory management operations. The computer 50 may comprise any computing device, such as a mainframe, server, personal computer, workstation, laptop, handheld computer, telephony device, network appliance, virtualization device, storage controller, network controller, etc.
Any suitable CPU 52 and operating system may be used. For example, CPU 52 may represent any of a wide variety of control logic including, but not limited to one or more of a microprocessor, a programmable logic device (PLD), programmable logic array (PLA), application specific integrated circuit (ASIC), a microcontroller, and the like, although the present description is not limited in this respect. In one embodiment, CPU 52 includes one or more Intel® compatible processors. Processors of CPU 52 may have an instruction set containing a plurality of machine level instructions that may be invoked, for example by an application or operating system.
The controllers 62a, 62b . . . 62n may include a system controller, peripheral controller, memory controller, hub controller, I/O bus controller, video controller, network controller, storage controller, etc. For example, a storage controller can control the reading of data from and the writing of data to the storage 64 in accordance with a storage protocol layer. The storage protocol of the layer may be any of a number of suitable storage protocols. Data being written to or read from the storage 64 may be cached in accordance with appropriate caching techniques.
A network controller can include one or more protocol layers to send and receive network packets to and from remote devices over a network 70. The network 70 may comprise a Local Area Network (LAN), the Internet, a Wide Area Network (WAN), Storage Area Network (SAN), etc. Embodiments may be configured to transmit data over a wireless network or connection. In certain embodiments, the network controller and various protocol layers may employ the Ethernet protocol over unshielded twisted pair cable, token ring protocol, Fibre Channel protocol, etc., or any other suitable network communication protocol. In some embodiments, the computer 50 may not be connected to a network 70 or may lack storage 64.
A video controller can render information on a display monitor, and may be embodied on a video card or integrated on integrated circuit components mounted on the motherboard. Certain of the devices may have multiple cards or controllers. An input device 72 is used to provide user input to the computer 50, and may include a keyboard, mouse, pen-stylus, microphone, touch sensitive display screen, or any other suitable activation or input mechanism. An output device 74 is capable of rendering information transmitted from the processor CPU 52, or other component, such as a display monitor, printer, storage, speaker, etc.
In certain embodiments, a circuit board embodiment having one or more reinforcement flanges in accordance with the present description may be embodied in a computer system including a video controller to render information to display on a monitor coupled to a computer system comprising a desktop, workstation, server, mainframe, laptop, handheld computer, etc. Alternatively, the circuit board embodiments may be embodied in a computing device that does not include a video controller, such as a switch, router, etc.
A network controller or other devices described herein may be mounted on an expansion card, such as a Peripheral Component Interconnect (PCI) card, PCI-express or some other I/O expansion card coupled to a motherboard, or on integrated circuit components mounted on the motherboard. Integrated circuit dies may be packaged individually, or packaged with other dies in stacks or other arrangements within a package. Thus, circuit board embodiments may be embodied in computer systems or other systems in which one or more reinforcement flanges in accordance with the present description are disposed on one or both of a motherboard and an expansion card. Accordingly, in some system embodiments, the system may lack an expansion card, and a reinforcement flange in accordance with the present description may be disposed on a motherboard. In another system embodiment, a reinforcement flange in accordance with the present description may be disposed on an expansion card but not on a motherboard.
Details on the PCI architecture are described in “PCI Local Bus, Rev. 2.3”, published by the PCI-SIG. Details on the Fibre Channel architecture are described in the technology specification “Fibre Channel Framing and Signaling Interface”, document no. ISO/IEC AWI 14165-25. Details on the Ethernet protocol are described in publications including “IEEE std. 802.3,” published Mar. 8, 2002, and “IEEE std. 802.11,” published 1999-2003.
The conductors of the board 104, including the pads 106, traces 112, plated vias 110 and reinforcement flanges 120, may be formed by any suitable process including those known to practitioners skilled in the art of circuit board fabrication. For example, the conductors may be formed utilizing solder mask defined (SMD) or metal defined (MD) techniques or any other suitable process. Still further, the conductors of the board 104, including the pads 106, traces 112, plated vias 110 and flanges 120, may be formed of any suitable conductive material, including metals such as copper, silver, gold, aluminum or any alloy thereof, or any other material capable of conducting electrical signals.
In the device 100 of the illustrated embodiment, each pad 106 is generally round in shape. More particular, the pad 106 of
Also, each trace 112 is generally elongated and defines a second maximum width W2 adjacent each pad 106. In the illustrated embodiment, the trace 112 has a generally constant width adjacent the pad 106. Hence, the average width AW2 of the trace 112 is substantially equal to the maximum width W2 of the trace 112 adjacent the pad 106. As best seen in
In the illustrated embodiment, the reinforcement flange 120 of
The reinforcement flange 120 includes a concave portion 122 which extends from the pad 106, and a convex portion 124 which extends to the trace 112, thereby electrically coupling the pad 106 to the trace 112. In addition, the flange 120 structurally reinforces the pad 106 and the trace 112 adjacent to the pad 106.
As best seen in
In another aspect of the present description, the pad 106 defines a center C1 and the reinforcing flange 120 defines a center C3 which is offset from the center C1 of the pad 106 by a distance D. In one embodiment, the center C3 of the flange 120 may be offset a distance D approximately ⅓ to ¼ the pad maximum width W1 of the pad 106. In another example, the flange 120 may overlap the pad 106 by 25-75% to provide an extruded or extended appearance as shown. Again, it is appreciated that other positions of the reinforcement flange, pad and trace may be suitable for reducing stress fractures or other failures, depending upon the particular application.
In yet another aspect of the present description, the flange 120 extends from the pad 106 to the trace 112 by a distance E. In one embodiment, the flange may extend a distance E approximately ⅓ to ¼ the pad maximum width W1 of the pad 106. For example, the flange may extend a distance E approximately equal to 5-8 mils. Again, it is appreciated that other relative sizes of the reinforcement flange, pad and trace may be suitable for reducing stress fractures or other failures, depending upon the particular application.
It is further appreciated that pads 106 may be selected for reinforcement with reinforcement flanges in a manner which depends upon the particular application. Thus, in the embodiment of
In another operation, solder joints are formed (block 210) between the package and pads of the substrate wherein each solder joint joins a solder ball to an associated pad of the substrate. In the illustrated embodiment, the package 10 is placed on the board 104 with the solder balls 30 of the package 10 engaging corresponding pads 106, 108 of the board 104. The pads 106, 108 are typically arranged in a pattern which matches that of the solder balls 30. The assembly may then be heated to a degree which permits the solder balls to melt. Once the solder cools and solidifies, the solder joint 22 is formed.
In yet another operation, connections between pads and traces are reinforced (block 220) using flanges, each flange being disposed on the substrate and extending from and joining an associated pad to an associated trace. In the illustrated embodiment, each flange has a third maximum width W3 at least one half the width of the first maximum width W1 of the pads. For example, the diameter of the flange 120 may be approximately ⅔ the diameter of the pad 106. As another example, the diameter of the flange 120 may be approximately equal to the diameter of the pad 106. Such an arrangement is believed to reduce fractures or other connection failures which may be caused during straining, stress or flexure of the board 104 during testing or further assembly.
The illustrated operations of
The foregoing description of various embodiments has been presented for the purposes of illustration and explanation. It is not intended to be exhaustive or to limit to the precise form disclosed. Many modifications and variations are possible in light of the above teaching.