Patent Application
20080128854
Embodiments of the present invention generally relate to the field of integrated circuit packages, and, more particularly to an embedded array capacitor with top and bottom exterior surface metallization.
Array capacitors are being embedded in the substrates of high frequency integrated circuit packages to manage power delivery to the die(s). Core layers, which are generally removed to make room for array capacitors, tend to be thicker and less resistive than build up layers. Therefore, the removal of core layers tends to result in a high package resistance.
The present invention is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like references indicate similar elements, and in which:
In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the invention. It will be apparent, however, to one skilled in the art that embodiments of the invention can be practiced without these specific details. In other instances, structures and devices are shown in block diagram form in order to avoid obscuring the invention.
Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.
Capacitor plates 102 represent a plurality of conductive plates separated by insulators to store a charge. In one embodiment, capacitor plates 102 comprise about 500 layers.
Top surface metallization 104 represents metal such copper that has been deposited or formed on an exterior surface of array capacitor 100 and couples with one or more vertical vias 106. While the thickness of top surface metallization can vary, in one embodiment top surface metallization 104 is about 75 micrometers thick.
Vertical vias 106 represent metalized terminals that can carry current as part of a power deliver solution for an integrated circuit package, for example, as shown in
Bottom surface metallization 108 represents metal such as copper that has been deposited or formed on an exterior surface of array capacitor 100 and couples with one or more vertical vias 106. One skilled in the art would appreciate that the addition of top surface metallization 104 and bottom surface metallization 108 can lower the resistance of an integrated circuit package which had core layers removed to accommodate an array capacitor.
Dielectric layers 302 represent organic dielectric material, such as epoxy based dielectric, that has been added to a substrate as part of a build-up process. Metal traces, not shown, may be included in dielectric layers 302 to route signals to and from die 310. To accommodate array capacitor 100, a portion of dielectric layers 302 may be removed, by etching or drilling for example, to expose micro-vias, or conductive elements coupled with package connections 304.
Package connections 304 provide an interface between IC package 300 and other components, for example through a socket. In one embodiment, signals are routed through package connections 304 to traces in dielectric layers 302 while power and ground are routed through package connections 304 to metallization regions on the bottom surface of array capacitor 100.
Micro-vias 306 may be formed on top of metallization regions on the top surface of array capacitor 100 as part of a manufacturing process to route the vertical vias in array capacitor 100 to the top of the package substrate.
Die bumps 308 may provide the mechanical and electrical connection between micro-vias 306 and die 310.
Die 310 may represent any type of integrated circuit device or devices that may benefit from the use of an array capacitor with top and bottom exterior surface metallization, for example a multi-core processor.
Processor(s) 402 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 invention is not limited in this respect. In one embodiment, processors(s) 402 are Intel® processors. Processor(s) 402 may have an instruction set containing a plurality of machine level instructions that may be invoked, for example by an application or operating system.
Memory controller 404 may represent any type of chipset or control logic that interfaces system memory 406 with the other components of electronic appliance 400. In one embodiment, the connection between processor(s) 402 and memory controller 404 may be referred to as a front-side bus. In another embodiment, memory controller 404 may be referred to as a north bridge.
System memory 406 may represent any type of memory device(s) used to store data and instructions that may have been or will be used by processor(s) 402. Typically, though the invention is not limited in this respect, system memory 406 will consist of dynamic random access memory (DRAM). In one embodiment, system memory 406 may consist of Rambus DRAM (RDRAM). In another embodiment, system memory 406 may consist of double data rate synchronous DRAM (DDRSDRAM).
Input/output (I/O) controller 408 may represent any type of chipset or control logic that interfaces I/O device(s) 412 with the other components of electronic appliance 400. In one embodiment, I/O controller 408 may be referred to as a south bridge. In another embodiment, I/O controller 408 may comply with the Peripheral Component Interconnect (PCI) Express™ Base Specification, Revision 1.0a, PCI Special Interest Group, released Apr. 15, 2003.
Network controller 410 may represent any type of device that allows electronic appliance 400 to communicate with other electronic appliances or devices. In one embodiment, network controller 410 may comply with a The Institute of Electrical and Electronics Engineers, Inc. (IEEE) 802.11b standard (approved Sep. 16, 1999, supplement to ANSI/IEEE Std 802.11, 1999 Edition). In another embodiment, network controller 410 may be an Ethernet network interface card.
Input/output (I/O) device(s) 412 may represent any type of device, peripheral or component that provides input to or processes output from electronic appliance 400.
In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of the present invention. It will be apparent, however, to one skilled in the art that the present invention may be practiced without some of these specific details. In other instances, well-known structures and devices are shown in block diagram form.
Many of the methods are described in their most basic form but operations can be added to or deleted from any of the methods and information can be added or subtracted from any of the described messages without departing from the basic scope of the present invention. Any number of variations of the inventive concept is anticipated within the scope and spirit of the present invention. In this regard, the particular illustrated example embodiments are not provided to limit the invention but merely to illustrate it. Thus, the scope of the present invention is not to be determined by the specific examples provided above but only by the plain language of the following claims.
