Title: Socket and package power/ground bar apparatus that increases current carrying capacity resulting in higher IC power delivery
Abstract: A socket and package apparatus are disclosed for increasing the amount of power that can be delivered from an IC board to an IC where the IC package is mounted in a socket connected to the IC board. The apparatus has two separable and distinct parts designed to electrically engage. The package is designed with a power bar where the panels of the power bar are permanently and electrically connected to various power planes of the IC package along its entire adjacent wall. The socket is designed with a power bar carrier designed to maximize the current flow from the IC board to the power bar. The package is then engaged into the socket.
Patent Number: 6,992,378 Issued on 01/31/2006 to Xie, et al.
| Inventors:
|
Xie; Hong (Phoenix, AZ);
Stone; Brent (Gilbert, AZ)
|
| Assignee:
|
Intel Corporation (Santa Clara, CA)
|
| Appl. No.:
|
753327 |
| Filed:
|
December 30, 2000 |
| Current U.S. Class: |
257/700; 257/686; 257/668; 257/778; 257/678 |
| Current Intern'l Class: |
H01L 23/12 (20060101); H01L 23/02 (20060101); H01L 29/40 (20060101) |
| Field of Search: |
257/700,686,778,678,668
361/788
439/309
|
References Cited [Referenced By]
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| 6672912 | Jan., 2004 | Figueroa.
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| 2002/0000645 | Jan., 2002 | Sato et al.
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| 2004/0100778 | May., 2004 | Vinciarelli et al.
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| Foreign Patent Documents |
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| |
| 2000/-456833 | Jun., 2000 | JP.
| |
Primary Examiner: Kielin; Erik
Assistant Examiner: Mitchell; James M.
Attorney, Agent or Firm: Blakely, Sokoloff, Taylor & Zafman LLP
Claims
What is claimed is:
1. An integrated circuit (IC) apparatus, comprising:
an IC socket having a power bar carrier at its center and one or more pin receptacles,
along an outer periphery wherein the power bar carrier includes a first conducting
panel electrically coupled to a first plurality of conducting pads;
a first activation mechanism to cause the power bar carrier to engage a power
bar incorporated on an IC package with a first force; and
a distinct second activation mechanism to cause the one or more pin receptacles
to engage one or more pins incorporated on the IC package with a second force,
wherein the first force and the second force are substantially equivalent.
2. The IC apparatus of claim 1, wherein the first conducting panel further includes
one or more conducting contacts extending beyond the periphery of the conducting
panel and coupled to the first conducting panel.
3. The IC apparatus of claim 2, wherein the first conducting panel and the one
or more conducting contacts are stamped from a single conducting foil.
4. The IC apparatus of claim 2, wherein the one or more conducting contacts are
compressibly and electrically engageable.
5. The IC apparatus of claim 2, wherein the one or more conducting contacts are
comprised of a bent conducting material.
6. The IC apparatus of claim 2, wherein the one or more conducting contacts further
comprise a spring constant.
7. The IC apparatus of claim 1, wherein the power bar carrier further includes
a second conducting panel electrically coupled to a second plurality of conducting pads.
8. The IC apparatus of claim 7, wherein the second conducting panel is insulated
from the first conducting panel.
9. The IC apparatus of claim 1, further comprising an activation mechanism that
causes the power bar carrier to engage a power bar of a corresponding IC package.
10. An integrated circuit (IC) power delivery system, comprising:
an IC socket including a power bar carrier at its center and one or more pin
receptacles, along an outer periphery wherein the power bar carrier includes a
first conducting panel electrically coupled to a first plurality of conducting
pads;
an IC package including a first power plane and a power bar incorporated on said
IC package comprising a first conducting panel electrically connected to the first
power plane along a first adjacent edge;
a first activation mechanism to cause the power bar carrier to engage a power
bar of corresponding IC package with a first force; and
a distinct second activation mechanism to cause the one or more pin receptacles
to engage one or more pins incorporated on said package with a second force, wherein
the first force and the second force are substantially equivalent.
11. The IC power delivery system of claim 10, wherein the IC package further includes:
a second power plane electrically isolated from the first power plane; and
a second conducting panel electrically connected to the second power plane of
the IC package along a second adjacent edge.
12. The IC power delivery system of claim 11, wherein the power bar further includes
a non-conducting insulation panel separating the first conducting panel from the
second conducting panel.
13. The IC power delivery system of claim 12, wherein the power bar further includes
one or more conducting bumps electrically connected to one or more of the first
conducting panel and the second conducing panel.
14. The IC power delivery system of claim 10, wherein the power bar further includes
one or more conducting bumps electrically connected to the first conducting panel.
15. The IC power delivery system of claim 10, wherein the first conducting panel
further includes one or more conducting contacts extending beyond the periphery
of the conducting panel and coupled to the first conducting panel.
16. The IC power delivery system of claim 15, wherein the first conducting panel
and the one or more conducting contacts are stamped from a single conducting foil.
17. The IC power delivery system of claim 15, wherein the one or more conducting
contacts are compressibly and electrically engageable.
18. The IC power delivery system of claim 15, wherein the one or more conducting
contacts are comprised of a bent conducting material.
19. The IC power delivery system of claim 15, wherein the one or more conducting
contacts further comprise a spring constant.
20. The IC power delivery system of claim 10, wherein the power bar carrier further
includes a second conducting panel electrically coupled to a second plurality of
conducting pads.
21. The IC power delivery system of claim 20, wherein the second conducting panel
is insulated from the first conducting panel.
Description
COPYRIGHT NOTICE
Contained herein is material that is subject to copyright protection. The
copyright owner has no objection to the facsimile reproduction of the patent disclosure
by any person as it appears in the Patent and Trademark Office patent files or
records, but otherwise reserves all rights to the copyright whatsoever.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates generally to the field of Surface Mount Technology (SMT)
Package and Socket Designs. More particularly, the invention relates to providing
a power bar and power bar carrier for increasing power and ground current throughpputs
between an Integrated Circuit (IC) board and an IC chip while equalizing load and
current distribution.
2. Description of the Related Art
With the increased demand for computer functionality and speed, improvements
are always being made in technologies that affect the ability of an IC board to
deliver power to components that reside on the IC board. Because of manufacturing
concerns, package stress factors, cost of materials, etc., each generation of technological
advances provide some benefit to the existing state of technology capability and
provides a segue into the next generation of technological innovation. With the
advent of Surface Mount Technology ("SMT"), certain ICs that may be modified, coded
or evolve in later generations, so that boards containing these ICs could be easily
upgraded, created a practical upgrade and replacement problem.
The solution to this problem resulted in sockets as place-holders and carriages
for these evolving ICs. The sockets are surface mounted onto the IC board during
the solder re-flow and then the chips requiring socket placement are easily placed
and removed from the board when required. As technologies have improved, the traces
that connect the power and ground sources of the IC board to the chip have become
a limitation because ICs require increasingly more power delivered through the
socket. For instance, present SMT socket sizes limit the number of pins to about
800 pins. Of these 800 pins, many will be designated for I/O type signals and the
rest are connected to either power or ground planes. As technologies improved for
development of the IC and more computational power is attained for any given IC,
bottlenecks are created by pin limitations for supplying the power from the IC
board to these ever increasingly power hungry IC chips. The problem arises because
even though more pins are designated for power transfer, the pin number limitation
and the pin and trace size limitation impose natural restrictions on the amount
of current that can be transferred across a set of multiple pins designated to
a power plane. One of the primary bottleneck limitations is generated by the chip
pins and the corresponding socket traces providing the power to those pins. Each
pin limits the current going through the pins to between one half of an amp to
one amp. Additionally, the electrical power delivery performance is limited by
the area where the package pin and socket trace make contact. Because of the limited
size of each pin and its corresponding contact area, the resulting resistance and
inductance of the contact reduces the current delivery for each pin or provides
inconsistent power transfer between one pin and another pin because of irregularities
in the contact.
FIG. 12 demonstrates a prior art socket 1210 engaging an IC package 1211.
All of the package pins 1201 are inserted into and engage a socket's pin
receptacles 1202. A lever 1203 is used for locking the socket pins
into place and forcing contact between the pins and their corresponding receptacles.
Because of the small size of the pins, limited force can be applied to the pins
resulting in inconsistent power transfer results. Additionally, each package pin
and socket trace limits the amount of current that can be passed through the pin.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
The present invention is illustrated by way of example, and not by way of limitation,
in the figures of the accompanying drawings and in which like reference numerals
refer to similar elements and in which:
FIG. 1 is a high level depiction of a socket and an IC package according to
one embodiment the invention.
FIG. 2 is a top view of a socket where several pin receptacles are electrically connected.
FIGS. 3
a and 3
b illustrate an IC package having a power
bar according to one embodiment of the invention.
FIG. 4 is a simplified socket according to one embodiment of the invention.
FIG. 5 demonstrates how a package power bar may be mounted in a socket carrier
according to one embodiment of the invention.
FIG. 6 is a socket with a cross-sectional view of a power bar according to one
embodiment of the invention.
FIGS. 7
a and 7
b demonstrate a carrier engaging a power
ba according to one embodiment of the invention r.
FIG. 8 is an example of how a carrier side may be stamped from an electrically
conducting foil according to one embodiment of the invention.
FIG. 9 illustrates how two foils may be mounted with insulation to form a carrier
according to one embodiment of the invention.
FIGS. 10 and 11 show alternative activation mechanisms for a carrier to engage
a power bar according to one embodiment of the invention.
FIG. 12 provides a prior art socket engaging a prior art package.
FIG. 13 is a top view of a prior art socket.
DETAILED DESCRIPTION OF THE INVENTION
An IC socket and corresponding IC package are described for increasing the ability
to transfer power from an IC board to an IC. The apparatus encompasses a socket
including a power bar carrier. The power bar carrier receives a corresponding power
bar incorporated on the IC package.
In the following description, for the purposes of explanation, numerous specific
details are set forth in order to provide a thorough understanding of the present
invention. However, the present invention may be practiced without some of the
specific detail provided therein. The invention is described herein primarily in
terms of a SMT socket designed to receive an IC with at least one power bar. The
power bar improves current transfer while reducing contact resistance and inductance
created by current power pin contact sizes.
The invention, however, is not limited to this particular embodiment alone, nor
is it limited to use in conjunction with any particular combination of pins and
power bars nor is it limited to use in SMT environments. For example, the claimed
apparatus may be used in conjunction with any IC board where utilization of a power
bar manufactured package improves power delivery to the IC and the board assembly
technology supports it.
DETAILED DESCRIPTION
FIG. 1 illustrates a high level depiction of socket and IC package according
to one embodiment of the invention. An IC package 101 having a power plane
(not shown) is mounted into a socket 103. The IC package 101 has
multiple input/output pins 104 that are inserted into corresponding socket
holes 105 for transferring and receiving informational input/output (I/O)
signals necessary for the proper functional operation of the IC chip 106
integrated with the IC package 101. Although other electrically conductive
materials may be used, in this embodiment a Copper (Cu) Power Bar 107 is
connected to the power plane 102 along its entire adjacent border 108
and extrudes from the IC package to be inserted into a corresponding power bar
carrier 109 incorporated in the socket 103. A locking mechanism 110
is employed to force the I/O the pin receptacle contacts to make contact with their
corresponding pins, while a second locking mechanism 111 may be employed
to separately lock the power bar carrier to the power bar.
FIG. 13 is a top view of a prior art socket 1310 (the view from which
the package would engage the socket) containing multiple pin receptacles 1311
that connect to pads for surface mounting on the underside of the socket. The pin
receptacles 1311 each have a corresponding contact 1312 for receiving
and abutting to the package pins when the IC package is engaged into the socket.
An insulated socket-housing barrier 1313 prevents any contact between any
of the pins 1311 and their respective contacts 1312 with any adjacent
pin. The pin size has been reduced over time due to chip complexity, solder re-flow
and packaging advances such as SMT and C4 technologies. Increased functionality
has resulted in increased power dissipation demands by the IC device to the point
where power and ground must be supplied through multiple pins. However, the pin
size and the contacts between the socket pin receptacle and the package pin limit
the power that may be supplied to an IC from an IC board. Additionally, the individual
pins cause high non-uniform current distribution between the different pins that
are utilized to supply the power to the IC package.
While FIG. 13 demonstrates the present state of the art, FIG. 2 conceptually
demonstrates a portion of the philosophy behind the innovative socket and corresponding
package enhancements from the socket perspective. Several pin receptacles 221
or contacts 222 designated for power transfer are electrically bound together
by a shorting piece of copper 223. Although the shorting piece of copper
is shown here as a trace for demonstration purposes, one embodiment contemplates
several pins and their shorting piece constructed from a single copper foil so
as to maximize the current surface area and distribution path. The pins may be
connected in any configuration that makes sense for the design of the IC package.
To accommodate the increased current capability of the new socket design, the IC
package should also be modified so that a bottleneck does not occur in the pins
transferring the power from the socket to the IC.
Multiple socket pin receptacles 225, that include I/O pin receptacles
or other pin receptacles where current throughput is not crucial, are connected
to multiple IC package pins, socket traces and contacts. Currently, each IC package
pin's known current carrying capacity, whether limited by the socket pin receptacle
or the IC package pin, is between 0.5 amps and 1 amp. Because pin utilization is
well known in the art, a complete discussion of their construction and implementation
is omitted.
An illustrative IC Package contemplated by the invention is shown in more detail
in FIGS. 3
a and 3
b. Although various planes or cross planes
may exist in the package for holding the power and ground for the IC, FIG. 3
a
demonstrates two power planes, one for holding a first voltage level and one
for holding a second voltage level. For simplicity these voltages levels will be
referred to as power and ground. By convention, the term "power" encompasses the
notion of ground and the nomenclature verbalized with reference to power planes
and power bars in this invention does not deviate from that convention. Arbitrarily,
the power plane 301 resides above the ground plane 302 although it
is well understood that location is irrelevant. Additionally, a plane in this context
is one level of copper although a plane that is not restricted to copper or a single
level is contemplated. For example, a ground plane could be constructed of any
conducting material and spread among several levels in the IC package 303.
The ground power plane's extrusion panel 304 could connect directly to one
or more of the ground planes along its entire adjacent edge 311 to the ground plane.
In this embodiment, a power bar 310 comprises two power plane extrusion
panels 304 and 305 that are separated by an insulating buffer panel
306 for protecting the integrity of the power signals to be delivered by
preventing short circuiting. The ground power plane extrusion panel 304
is connected along its entire adjacent bordering edge 311 to the ground
power plane 302 by solder or equivalent while the power plane extrusion
panel 305 is connected along its entire adjacent bordering edge to the power
plane 301 via solder or equivalent. An insulation barrier panel 307
along the perpendicular circumference of the power plane extrusion panel 305
isolates the power plane extrusion panel 305 from the ground plane 302
where the power plane extrusion panel 305 penetrates or passes through the
ground plane 302.
Each power or ground extrusion panel 304 or 305 of the power bar
310 may have various contact extrusions, bumps or ridges to enable intentional
engaging of the IC package power bar to a socket. In this embodiment, several protrusions
in the form of regularly spaced bumps or ridges 309 are integrally connected
and formed as part of the power or ground extrusion panels to assist in the intentional
engaging or locking in place of the IC package power bar to the socket carrier.
The power bar removes the inherent limitations of transferring power to an IC
through pins by providing a larger surface and contact area. The increased surface
and contact area provides substantial power delivery capabilities while also providing
a uniform delivery mechanism that reduces resistance and inductance caused by multiple pins.
FIG. 4 illustrates a power bar carrier portion of a socket according to one
embodiment where the carrier 410 has two electrically conducting side panels
401 and 402 separated by a non-conductive insulation bar 403.
The non-conductive insulating material may be formed from one mold or pieced together
to hold the various conductive power bar carriers and pin receptacles (not shown).
In this embodiment, the electrically conducting side panels 401 and 402
are separated by insulation in order to accommodate both power and ground power
plane extrusion panels 304 and 305 from a package power bar. Although
the power bar and the power bar carrier are shown to be a full length and straight
line design, the invention contemplates any shape of power bar and corresponding
power bar carrier. The power bar carrier and the power bar are always designed
to carry more current than the combination of pins that it replaces. At a minimum,
a power bar replaces two pins such that instead of having a bottleneck of the individual
pins, the socket configuration need only have one power bar design such that a
larger surface area exists where the surface area is inclusive of the size of the
individual pins plus the space that would normally have been insulation between
them. Optimally, although the design is not so limited, a power bar design accommodates
the replacement for all pins and pin receptacles that would normally be associated
with a given power plane in order to optimize current distribution, consistency
and power delivery capability.
The socket may ultimately be placed on an IC board, such as a Central Processing
Unit (CPU) motherboard. As the design contemplates use in a solder-flow process
used by existing technologies, such as SMT, the mounting pads 405 on the
bottom of the socket are produced by known methods and are spaced as required.
FIG. 5 demonstrates how a power bar carrier may be mounted into a socket. The
power bar 501 in this embodiment is made of several segments 502,
each designed to correspond with contact portions 503 of a carrier 504.
The power bar 501 is initially set into the carrier such that it begins
in a position where no contact is made. Upon sliding the power bar into position,
each of the segments align with their corresponding contacts and the spring portion
of the carrier's contacts apply the force necessary to establish the electrical connection.
FIG. 6 depicts a socket 600 with several input/output (I/O) type pin
receptacles 601 and a power bar carrier 602 that may be located in
the center of the socket 600. A cross-sectional view of a power bar 603
detached from the package sitting in the carrier 602 is also illustrated.
Although a power bar in which the entire surface of each power plane extrusion
panel contacts the entire contact surface of its corresponding electrically conducting
carrier panel is contemplated, this embodiment has contact bumps 604 so
that the package can engage the carrier by a physical shift that aligns the carrier
bumps with the power bar bumps as demonstrated in FIGS. 7
a and 7
b.
FIGS. 7
a and 7
b show a power bar 701 with power
and ground plane extrusion panels 702 and 703 having contact bumps
704 and the extruding contact bumps or bent contact spring elements 705
of the carrier's corresponding carrier foil. FIG. 7
a shows the power bar
before it is engaged with the socket carrier and FIG. 7
b illustrates the
power bar engaged with the socket carrier bumps. Because the power bar may have
a different alignment with the socket carrier than the I/O pins to the I/O pin
receptacles, as demonstrated in FIG. 1, the engagement shift 111 for the
power bar may be performed independently of the I/O pin engagement 110 for
the package to the socket. For instance, two activation mechanisms may exist on
the socket to engage the various types of receptacles. Similarly, a single activation
mechanism (not shown) may be used to engage the package pins while another activation
mechanism capable of applying pressure in a different direction may cause the power
bar to engage with the carrier. A discussion of how an activation mechanism causes
a socket to engage a corresponding package is omitted because such mechanisms are
well known in the art. In order to deliver the power efficiently, thereby reducing
contact resistance and inductance, the shape of the contacts and the power bar
can be different from those utilized for the pins. By separating the activating
mechanisms, more contact force may be applied to the power delivery contacts of
the power bar mechanism to further improve electrical performance. Although separate
activation methods have been described, a single activation mechanism that applies
necessary force for the pins and power bar's respective engagement is also contemplated.
FIG. 8 shows an example of how a copper or other electrically conducting foil
800 may be stamped to produce one of the carrier's conducting panels. In
this example, carrier panel contacts 801 for connecting to the power bar
bumps are cut and bent to provide enough tension to produce a frictional engagement
of the power bar. This type of bending of a conducting material is known to produce
a spring constant that may be efficiently accessed in the type of engagement mechanism
contemplated. The BGA pads are connected to extrusions 802 stamped at the
base of the foil to provide for a SMT soldering of the socket to an IC board. Two
foils 901 and 902 similar to those shown in FIG. 8 are sandwiched
in an insulating material 903 along their main conducting surfaces as shown
in FIG. 9. The entire carrier is then connected into a power bar socket
904 which is then capable of receiving a corresponding power bar package 905.
FIGS. 10 and 11 demonstrate two alternative embodiments where the power bar
is engaged by a spring type mechanism, here a bent carrier panel. In FIG. 10, a
single spring 1001 applies the contact for one power plane extrusion of
the power bar while pressing the power bar into contact with the other carrier
side 1002. Alternatively, FIG. 11 demonstrates a carrier employing two bent
spring panels 1101 to engage the respective panels of the power bar.
ALTERNATIVE EMBODIMENTS
The foregoing description has demonstrated several embodiments of the invention.
It is understood, however, that the invention need not be limited to any specific
embodiment and that all examples are only illustrative. Numerous other embodiments
that are limited only by the scope and language of the claims are contemplated
as would be obvious to someone possessing ordinary skill in the art and having
the benefit of this disclosure.
*
