U.S. patent application number 09/853279 was filed with the patent office on 2002-04-11 for processor power delivery system.
Invention is credited to Harrison, Joe A., Ruttan, Thomas G., Stanford, Edward R..
Application Number | 20020042214 09/853279 |
Document ID | / |
Family ID | 24709801 |
Filed Date | 2002-04-11 |
United States Patent
Application |
20020042214 |
Kind Code |
A1 |
Harrison, Joe A. ; et
al. |
April 11, 2002 |
Processor power delivery system
Abstract
A system for delivering power to a processor enables a DC-to-DC
converter substrate to be secured to the processor carrier in the
Z-axis direction. The ability to assemble the converter to the
processor in this way facilitates assembly compared to systems in
which the converter is plugged in to the processor carrier in the
direction substantially parallel to the surface of the
motherboard.
Inventors: |
Harrison, Joe A.; (Olympia,
WA) ; Stanford, Edward R.; (Dupont, WA) ;
Ruttan, Thomas G.; (Lake Oswego, OR) |
Correspondence
Address: |
TROP PRUNER & HU, PC
8554 KATY FREEWAY
SUITE 100
HOUSTON
TX
77024
US
|
Family ID: |
24709801 |
Appl. No.: |
09/853279 |
Filed: |
May 11, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09853279 |
May 11, 2001 |
|
|
|
09675283 |
Sep 29, 2000 |
|
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|
Current U.S.
Class: |
439/67 ;
29/830 |
Current CPC
Class: |
Y10T 29/49144 20150115;
H05K 2201/049 20130101; H05K 7/1092 20130101; H05K 1/0263 20130101;
H05K 2201/10325 20130101; H05K 2201/10378 20130101; H05K 2201/10734
20130101; H05K 3/325 20130101; H05K 2201/09345 20130101; G06F 1/189
20130101; Y10T 29/49117 20150115; H05K 2201/045 20130101; H05K
1/141 20130101; Y10T 29/49126 20150115; H05K 3/368 20130101; Y10T
29/4913 20150115 |
Class at
Publication: |
439/67 ;
29/830 |
International
Class: |
H05K 001/00; H01R
012/00; H05K 003/36 |
Claims
What is claimed is:
1. A method comprising: plugging a DC-to-DC converter on top of a
processor carrier in turn secured to a motherboard; and providing
substantially planar power and ground contacts on said converter
and said processor carrier; and engaging said contacts on said
converter with said contacts on said carrier through a resilient
interconnect having resilient electrical contacts.
2. The method of claim 1 including clamping said converter onto
said processor carrier.
3. The method of claim 1 including forming power and ground regions
of the contacts of said processor carrier and said converter and
interdigitating said power and ground regions.
4. The method of claim 1 including plugging said converter into
said processor carrier.
5. The method of claim 1 including providing compressible contacts
in said interconnect and compressing said contacts between said
converter and said carrier.
6. The method of claim 5 including maintaining electrical
continuity through said interconnect via said electrical contacts
and aligning said contacts on said converter to said carrier by
inserting at least one pin through said interconnect and said
converter.
7. The method of claim 1 including forming a interconnect sheet
with holes in said sheet and molding said contacts in said
holes.
8. A interconnect comprising: a non-conductive polymer film; and a
plurality of conductive polymer contacts formed in said film.
9. The interconnect of claim 8 wherein said film includes opposed
surfaces and said contacts extend above a surface of said film.
10. The interconnect of claim 9 wherein said contacts extend above
both opposed surfaces of said film.
11. The interconnect of claim 10 including at least two alignment
holes.
12. The interconnect of claim 2 wherein said contacts are
resilient.
13. A motherboard comprising: a circuit board; a processor carrier
on said board; a DC-to-DC converter secured on said carrier; and a
film layer sandwiched between said carrier and said converter, said
film layer including conductive polymer contacts in said film
layer.
14. The motherboard of claim 13 wherein said conductive polymer
contacts extend above said film layer.
15. The motherboard of claim 13 wherein said conductive polymer
contacts electrically couple contacts on said converter and said
carrier.
Description
BACKGROUND
[0001] This invention relates generally to power delivery to
electronic circuits and particularly to an improved power delivery
system for supplying power from a power source to a processor.
[0002] In a typical computer system, a large printed circuit known
as a "motherboard" contains a number of basic components. The
motherboard is supplied with voltage from a power supply. The
motherboard includes connectors for daughter boards that can be
plugged in to provide additional capabilities. Such boards, for
example, may provide an interface to disk drives and compact disk
read only memories, and may provide modem interfaces for local area
networks and the like.
[0003] Processors operate at lower voltages than some other
components on the motherboard. However, because of their high
speed, processors consume large amounts of power despite the fact
that they use lower voltages. Since the processor is operating at a
low voltage with high power, the current required by the processor
is large. A localized DC-to-DC converter (known as a voltage
regulator module (VRM) or power pod) reduces the main supply
voltage for supplying the processor, for example. Typically for
Intel 32 bit processors, this DC-to-DC converter plugs into a
connector on the motherboard. The lower voltage is then conducted
through printed circuit traces on the motherboard to the processor
socket. For higher current Intel 64 bit processors, the DC-to-DC
converter connects directly to the processor package through an
edge connector because of the high loss associated with conveying
power through two connectors and the motherboard as in Intel 32-bit
systems. The power connector may also provide signal connections
related to power supply issues.
[0004] Conventionally, the processor is plugged into the
motherboard in a direction that is transverse to the plane of the
motherboard. If the plane of the motherboard defines the X and Y
directions, the processor is plugged into the motherboard in the
Z-axis direction. In other words, the processor is moved from a
position above the motherboard downwardly to plug into the
motherboard. Conventionally, the DC-to-DC converter is plugged onto
the processor package edge in a direction that is generally
parallel to the surface of the motherboard (transverse to the
Z-axis direction).
[0005] This configuration results in a number of difficulties. With
the processor already attached to the motherboard, the action of
plugging the converter into the processor carrier along the surface
of the motherboard (e.g., the X-axis direction) is prone to
interference from upwardly directed components already on the
motherboard. Moreover, there is little room to manipulate the
converter connections along the motherboard. The interconnection of
the converter and the processor carrier is awkward, increasing the
demands on assembly workers and requiring more elaborate
interconnection devices. A complex rigid mount mechanism is used to
align the processor package and the DC-to-DC converter in both the
Z and X axis. This takes up a large amount of motherboard real
estate.
[0006] Thus, there is a need for an improved way of delivering
power to a processor package edge.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is a side elevational view of one embodiment of the
invention in the course of assembly;
[0008] FIG. 2 is a top plan view of the embodiment shown in FIG.
1;
[0009] FIG. 3 is an enlarged, partial, bottom plan view of the
DC-to-DC converter substrate planar power contacts shown in FIG.
1;
[0010] FIG. 4 is a cross-sectional view taken generally along the
line 4-4 in FIG. 2;
[0011] FIG. 5 is a partial exploded view of the embodiment shown in
FIG. 4; and
[0012] FIG. 6 is a top plan view of a component shown in FIG.
5.
DETAILED DESCRIPTION
[0013] Referring to FIG. 1, a processor power delivery system 10
enables a DC-to-DC converter 12 to be assembled to a processor
carrier 18 in the Z-axis. The Z-axis (indicated by an arrow in FIG.
1) is the direction that is transverse to the surface of a
motherboard 28 and transverse to the lengths of the converter 12
and the processor carrier 18.
[0014] The processor carrier 18 may be plugged into a socket 50
that in turn plugs into a motherboard 28, all in the Z-axis
direction. A processor 52 may be attached on the carrier 18, for
example using surface mount solder balls 20, to a connection layer
21. Thereafter, the converter 12, including components 54, may
plugged atop the processor carrier 18 also in the Z-axis direction.
This greatly facilitates the connection of the two units.
[0015] The converter 12 includes contacts 16 on its lower surface
14 to make direct surface to surface contact with the processor
carrier 18. The contacts 16 communicate with the converter 12
components 54 through vias (not shown). The processor carrier 18
includes contacts 22 on its upper surface that mate with the
contacts 16 when the carrier 18 and converter 12 are edge combined.
The contacts 22 eventually electrically connect to power supply
pins (not shown) on the processor 52 through connection layer 21.
In one embodiment, the contacts 16 and 22 may each be formed of a
copper land pattern.
[0016] A pair of upstanding alignment pins 24a and 24b on the
processor carrier 18 pass through holes (not shown in FIG. 1) in
the converter 12. This pin/hole connection aligns the contacts 16
and 22 and facilitates the clamping engagement between the
converter 12 and the processor carrier 18.
[0017] Thus, referring to FIG. 2, the pins 24a and 24b pass
completely through the converter 12 in one embodiment of the
present invention. This engagement aligns the contacts 16 and 22
with respect to one another as the converter 12 is pressed down
into firm engagement with the processor carrier 18 in the Z-axis
direction.
[0018] Referring to FIG. 4, the converter 12 laps over an edge and
electrically engages, in direct surface to surface contact, the
processor carrier 18. The converter 12 and processor carrier 18 may
be clamped together using clamping devices 38 and clamping housing
58. In one embodiment of the present invention, the pins 24 may be
threaded and may be secured using threaded fasteners. However,
other clamping devices may be utilized to maintain an even clamping
force along the length of the contacts 16 and 22.
[0019] Referring to FIG. 3, the contacts 16 of the converter 12
include a first set of planar interdigitated contacts 16a that may
provide a power supply (Vcc) connection. A second set of planar
interdigitated contacts 16b may provide the ground (Vss) or return
power connection. The interdigitation may be achieved through
fingers 40, in one embodiment of the present invention. The
interdigitation of the fingers 40 reduces the inductance of the
power contacts 16a and the ground contacts 16b since mutual
inductance is cancelled out by the interdigitated arrangement.
[0020] Power control signals (such as a PWRGOOD signal) may also
pass through the contacts 16 from the contacts 22. For example, a
plurality of isolated power signal vias 34 may extend through the
contacts 16. Similarly, vias 36 may pass through the process planar
power contacts 22. The arrangement of the signal vias 34 and 36 is
subject to considerable variation.
[0021] Alignment holes 26 are provided on the converter 12 for
engagement with the alignment pins 24 on the processor carrier 18.
The arrangement of the contacts 22 may be identical to that shown
in FIG. 3 with the exception that the contacts 22 may include vias
36 to an internal copper land pattern (not shown) and may further
include the vias 34 which extend through the contacts 16 for
conduction of other signals.
[0022] The processor power delivery system 10 may include a
plurality of components that may be resiliently clamped together
between the housing 58 and the motherboard 28 as shown in FIG. 5.
The housing 58 may include an upper surface with a plurality of
reinforcing ribs 62 and a body 60. Formed in the body 60 is a
corrugated spring 64. The ends 66 of the spring 64 may be held
within the body 60 for example by molding the spring 64 into the
body 60.
[0023] When the body 60 is pressed against the converter 12, the
spring 64 vees are compressed, applying a uniform force through the
body 60 to the converter 12. In one embodiment, the spring 64 may
be formed of beryllium copper. It may be shaped in a corrugated
shape with a plurality of vees extending into the spring 64 from
above and below. Each of the vees may form a V-shaped compression
spring pressed against either the body 60 or the converter 12. The
arrangement of the corrugated spring 64 serves to make more uniform
the forces applied through the body 60.
[0024] Ideally, the housing 58 supplies a substantially constant
pressure over the life of the system 10. The spring 64 may be
defined with the cold flow properties of the related substrates
over time in mind. The housing 58 may be formed of extruded
aluminum or plastic as two examples. In one embodiment, the housing
58 may be hinged and latched to clear the contact region and to
allow for Z-axis assembly or replacement of components while
providing a registration feature to align the underlying
substrates.
[0025] Sandwiched between the converter 12 and the processor
carrier 18 is a relatively low profile conductive polymer
interconnect 68 including a polymer film 70 having captured therein
conductive polymer contacts 72. In one embodiment of the present
invention, the film 70 may be formed of kapton and the polymer
contacts 72 may be formed of a polymer that has been made
conductive for example by doping it with conductive particles such
as silver particles or oriented metallic wires. In each case, the
polymer contacts 72 may be formed of a plastic material that is
relatively resilient so that the material may be compressed between
the converter 12 and the carrier 18. The polymer contacts 72
produce a conductive contact between the converter 12 and the
carrier 18. Moreover, because of the resilient nature of the
interconnect 68, surface irregularities may be accounted for and
more reliable interconnection may be achieved in some cases.
[0026] In some embodiments, the conductive polymer contacts 72 may
be substantially thicker than the film 70. For example, in one
embodiment, the contacts 72 may have a thickness four times that of
the film 70.
[0027] As shown in FIG. 6, the interconnect 68 includes a pair of
openings 74 to receive and pass the alignment pins 24a and 24b. The
alignment pins 24a and 24b also act to precisely position the
contacts 72 with respect to the converter 12 and the carrier 18.
The pins 24a and 24b may extend upwardly through the interconnect
68 and the converter 12 and in one embodiment through the housing
58 for securement by securement devices 38 shown in FIG. 4. In
other cases, as mentioned previously, a hinged clamping device may
be positioned for selectively applying a clamping force to the
converter 12 and carrier 18 through the body 60 and the spring
64.
[0028] The contacts 16 and 22 may be brought into direct, planar
surface to surface contact with one another. The contacts 16 and 22
may be brought into direct engagement in the Z-axis direction, with
the converter 12 atop the processor carrier 18. With the
application of a compression force across the converter 12 and the
processor carrier 18, good electrical contact may be obtained. The
pins 56 on the socket 50 provide electrical communication with the
motherboard 28.
[0029] Because the converter 12 and the processor carrier 18 may
both be assembled in the Z-axis direction, the assembly of the
processor power delivery system 10 is facilitated. Of course, it is
not necessary that either the converter 12 or the processor carrier
18 be rigorously moved through the Z-axis direction. Instead,
either or both of the converter 12 and the processor carrier 18 may
be moved so as to have a component of displacement in the Z-axis
direction relative to the plane of the motherboard 28. Since the
contacts 16 and 22 meet along a common plane, the converter 12 may
be moved onto the processor carrier 18 at any angle between the
Z-axis and the plane of the motherboard 28.
[0030] The electrical performance may be optimized in some
embodiments by modifying the patterning of the contacts 16 and 22
without re-tooling converter 12 or carrier 18 assemblies. Some
embodiments may achieve a mechanical benefit from having a single
axis of assembly.
[0031] While an embodiment is illustrated in FIGS. 1 through 6
using planar contacts, embodiments of the present invention may be
applied to other designs as well. The combination of the spring 64
and the interconnect 68 may be particularly desirable because the
pressure applied by the spring 64 may result in more even pressure
applied to the conductive contacts 72 in some embodiments.
[0032] In an embodiment using conductive polymer contacts captured
in a kapton film, the film may be formed by molding the conductive
contacts into a previously formed film, as one example. Another way
of forming the interconnect 68 includes shaking conductive contacts
into holes in the film and then bonding the contacts in place.
Generally, pressure may be applied to the contacts to increase
their conductivity.
[0033] While the present invention has been described with respect
to a limited number of embodiments, those skilled in the art will
appreciate numerous modifications and variations therefrom. It is
intended that the appended claims cover all such modifications and
variations as fall within the true spirit and scope of this present
invention.
* * * * *