Patent Application
20050093120
The field of invention relates generally to computer systems and, more specifically but not exclusively relates to packaging schemes for voltage regulation modules.
An important aspect of any computer system is power provisioning. Generally, regulated power must be supplied to various system components, such as peripheral devices, circuit boards, and integrated circuits. Under a typical configuration, a power supply is used to convert alternating current (AC) input to various direct current (DC) voltage outputs that are supplied to the computer system. The power supply provides a certain level of power conditioning that is suitable for many of the system components. However, the voltage conditioning provided by the power supply is generally insufficient for powering critical components, such as the system processor(s).
In order to provide enhanced power conditioning, many systems employ a specially-configured voltage regulator or voltage regulation module (VRM). The voltage regulator or VRM receives “pre-conditioned” DC input from the power supply, and further conditions the input to remove transient voltages and the like. This power condition functionality is accomplished by passing the input voltage through various filter components, including passive and/or active filter elements. For a voltage regulator, the voltage regulation components are mounted directly on the motherboard (or other circuit board), while for a VRM the voltage regulation components are mounted to a separate board that is coupled to the motherboard (or other circuit board) via a connector. For many servers, the VRM is a detachable module that is coupled to the motherboard via a connector that employs a built-in locking mechanism to secure the module in place.
A typical voltage regulator mounting scheme is shown in
Processor package 104 includes a package substrate 110, a processor die 112, an integrated heat spreader (IHS) 114, and a heat sink 116. The underside of processor die 112 is “flip bonded” to package substrate 110 via a plurality of solder balls 118. The topside of the processor die is thermally coupled to IHS 114 via a thermal paste 120. Heat sink 116 will usually be coupled to IHS 114 in a manner that supports excellent heat transfer between the components, such as via a thermal paste 122. These coupling means further include solders and mechanical mounting techniques, such as mounting clips and the like.
An alternative conventional voltage regulator scheme is shown in
The conventional voltage regulator and VRM mounting schemes have several drawbacks. First, since the voltage regulation components or VRM are coupled to the motherboard, it is necessary to route power from the regulated voltage output through the motherboard to the processor. With the ever-increasing processor speeds, a corresponding increase in power consumption has followed. Since the supply voltage (e.g., 3.3 volts) to the processor must remain low, the heat generated via the power traces in the motherboard has increased in parallel with the increase in processor power consumption. This leads to overheating of the motherboard power traces and thermal stresses on solder connections 108 and/or the socket connections.
Other drawbacks relate to mechanical considerations. Typically, VRMs are placed into environments that employ forced convection cooling via one or more fans. The airflow over the VRM and/or other system components may induce mechanical resonances. These resonances may, in turn, be coupled into the connection between the VRM and the motherboard, leading to connection failures.
The foregoing aspects and many of the attendant advantages of this invention will become more readily appreciated as the same becomes better understood by reference to the following detailed description, when taken in conjunction with the accompanying drawings, wherein like reference numerals refer to like parts throughout the various views unless otherwise specified:
a and 1b are elevation cross-section views of conventional IC packaging schemes common to the prior art;
a and 2b respectively show elevation cross-section views of a first set of exemplary IC packaging schemes, according to an embodiment of the invention;
c is a plan view illustrating further details of how a voltage regulation module is connected to an integrated heat spreader in the embodiment of
d and 2e show interconnect layouts formed in an interconnect layer of an interconnect member, according to respective embodiments of invention;
a and 3b respectively show elevation cross-section views of a second set of exemplary IC packaging schemes, according to an embodiment of the invention;
a and 4b respectively show elevation cross-section views of a third set of exemplary IC packaging schemes, according to an embodiment of the invention; and
Embodiments of a detachable on package voltage regulation module are described herein. In the following description, numerous specific details are set forth to provide a thorough understanding of embodiments of the invention. One skilled in the relevant art will recognize, however, that the invention can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of 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, the 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.
In accordance with principles of the invention, embodiments of packaging schemes are disclosed herein that locate a voltage regulation module or voltage regulation components proximate to a processor or similar high-power integrated circuit in a manner that enhances mechanical robustness while reducing heat generation and failure modes found in the prior art. The packaging schemes include packages with on-package VRMs (or VRM components), eliminating the need to provide separate mounting provisions for a VRM or VRM components on a system's motherboard.
Details of IC packages 200A and 200B comprising a first set of exemplary embodiments of the invention are shown in
However, in contrast to the conventional packaging schemes of
An important consideration for each of the embodiments disclosed herein is the ability to provide electrical connectivity between the VRM and associated components. For example, there needs to be an electrical path between the connection points of the IC package (i.e., connectors 108) and the VRM to supply input power to the VRM. Additionally, there needs to be an electrical path between the output of the VRM and the substrate 110A, such that substrate 110A can provide the proper power input, and optionally, control input/output (I/O) signals to processor die 112.
Exemplary electrical connectivity layouts in which integrated heat spreader 204 serves a dual role as both a heat dissipation means and an interconnect member are shown in
In the embodiment of
Meanwhile, a separate interconnect layer or layers 218 is used for routing power input, power output, and control I/O signals between VRM 202 and substrate 110A via corresponding electrical traces formed in the layer(s). Since the IHS body will generally be made of a material that is electrically conductive (which is required if the IHS is to be used as a ground plane), an insulative layer 222 needs to be placed between interconnect layer 218 and the main body of IHS 204. Interconnect layer 218 may generally comprise a single layer, or may comprises multiple layers in a manner analogous to multiple routing layers employed in a multi-layer PCB. In general, the interconnect layer will include electrical routing provisions for at least the power output from the VRM. In some instances, further traces will be provided to provide electrical connections for control I/O signals that are passed between the processor and the VRM. The continuous line circuit traces shown in
The IHS assembly (i.e., body, insulative layer 220 and interconnect layer 218 may be formed using one of many well-known circuit forming techniques. For example, in one embodiment the body of IHS 204 comprises a metal, such as copper, which is coated with an insulative layer, such as silicon dioxide (SI02), using a conventional semiconductor manufacturing process. A plurality of electrical traces, made of a metal such as copper, silver, or gold, are then formed over the SI02 insulative layer using another well-known process for forming electrical traces, such as low pressure vapor deposition or chemical etching.
The thin dashed lines 228 shown in
An alternative configuration to the embodiment of
In general, PCB 210 of VRM 202 may be electrically coupled to the various traces, power, and ground planes provided by IHS 204 via one of several conventional connection techniques. These include, but are not limited to, wire bonds, mating connectors, and solder connections. For illustrative purposes, these connections are shown as connections 232.
IC packages 300A and 300B corresponding to a second set of exemplary embodiments of the invention are shown in
IC packages 400A and 400B corresponding to a third set of exemplary embodiments of the invention are shown in
A monitor 514 is included for displaying graphics and text generated by firmware, software programs and program modules that are run by computer system 500. A mouse 516 (or other pointing device) may be connected to a serial port, USB (Universal Serial Bus) port, or other like bus port communicatively coupled to processor 512. A keyboard 518 is communicatively coupled to motherboard 508 in a similar manner as mouse 516 for user entry of text and commands. In one embodiment, computer system 500 also includes a network interface card (NIC) 520 or built-in NIC interface (not shown) for connecting computer system 500 to a computer network 522, such as a local area network (LAN), wide area network (WAN), or the Internet.
Computer system 500 may also optionally include a compact disk-read only memory (“CD-ROM”) drive 524 into which a CD-ROM disk may be inserted so that executable files, such as an operating system, and data on the disk can be read or transferred into memory 510 and/or hard disk 506. Other mass memory storage devices may be included in computer system 500.
The above description of illustrated embodiments of the invention, including what is described in the Abstract, is not intended to be exhaustive or to limit the invention to the precise forms disclosed. While specific embodiments of, and examples for, the invention are described herein for illustrative purposes, various equivalent modifications are possible within the scope of the invention, as those skilled in the relevant art will recognize.
These modifications can be made to the invention in light of the above detailed description. The terms used in the following claims should not be construed to limit the invention to the specific embodiments 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.
