Title of Invention

ELECTRONIC ASSEMBLY WITH LATERALLY CONNECTED CAPACITORS AND MANUFACTURING METHOD.

Abstract An electronic assembly includes multiple discrete capacitors (504, Figure 5), which are surface mounted to or embedded within an electronic housing, such as an integrated circuit package (1504, Figure 15). One or more side terminals (510) of adjacent capacitors are electrically connected through lateral connections (512, 620, Figures 5, 6). These lateral connections provide an extremely low lateral inductance current path between the discrete capacitors. (FIG. - 6)
Full Text Electronic Assembly With Laterally Connected Capacitors and Manufacturing Method
Technical Field of the Invention
The present invention relates generally to apparatus for providing capacitance to an electronic circuit, and
more particularly to providing capacitance to an integrated circuit load, and methods of manufacturing an
electronic assembly that includes discrete capacitors electrically attached to a housing.
Background of the Invention
Electronic circuits, and particularly computer and instrumentation circuits, have in recent years
become increasingly powerful and fast. As circuit frequencies continue to escalate, with their associated
high frequency transients, noise in the power and ground lines increasingly becomes a problem. This noise
can arise due to inductive and capacitive parasitics, for example, as is well known. To reduce such noise,
capacitors known as bypassing capacitors are often used to provide a stable signal or stable supply of power
to the circuitry. Capacitors can also be used to suppress unwanted radiation, to dampen voltage overshoot
when an electronic device (e.g., a processor) is powered down, and to dampen voltage droop when the
device powers up.
Bypassing capacitors are generally placed as close as practical to a die load or "hot spot" in order to
increase the capacitors" effectiveness. Often, the bypassing capacitors are surface mounted to the die side or
land side of the package upon which the die is mounted, or embedded within the package itself. Figure 1
illustrates a cross-section of an integrated circuit package 102 having die side capacitors 106 ("DSC"), land
side capacitors 108 ("LSC"), and embedded chip capacitors 110 ("ECC") in accordance with the prior art.
Die side capacitors 106, as their name implies, are mounted on the same side of the package 102 as the
integrated circuit die 104. In contrast, LSCs 108 are mounted on the opposite side of the package 102 as the
die 104. ECCs 110 are embedded within the package 102.
Typically, multiple bypassing capacitors are used to provide the desired capacitance. Figure 2
illustrates a bottom view of an integrated circuit package 202 having multiple LSCs 204, which are
electrically connected to pads 206 on the bottom of the package 202 in accordance with the prior art The
terminals 208 of each capacitor 204 are connected to a different set of pads 206. The cross-hatching on
terminals 208 is intended to indicate that terminals 208 and pads 206 typically are connected, in an
alternating manner, to power and ground planes (not shown) within the package 202. Analogous figures
could be used to illustrate the connection of DSC terminals to package pads, or the connection of ECC
terminals to vias within the package.
Figure 3 illustrates a cross-sectional view of a portion of the integrated circuit package 202 and
LSCs 204 of Figure 2 along section lines 3-3. When LSCs are multi-layer capacitors, as shown, each
capacitor 204 includes multiple planes 302, 304 of conductive material, separated by layers of dielectric
material. Although only six planes are shown, numerous planes are usually present (e.g., hundreds of
planes).
Typically, conductive planes 302,304 are configured so that alternating planes connect to
alternating terminals 306,308 around the capacitor. This enables terminals 306,308 and planes 302,304 to
be connected, in an alternating manner, to pads 206 on the package body, as described in conjunction with
Figure 2. Pads 206, in turn, connect to either power or ground planes 314,316 within the package body
through plated or filled vias 318. Because the capacitors 204 are interconnected through different sets of
pads 206, vias 318, and power or ground planes 314,316 within the package, some "lateral" inductance
exists between the capacitors. In other words, the lateral current between capacitors 204 is carried over a
conductive loop having a loop area that is bounded by various conductive structures (e.g., pads, vias, and
power/ground planes) of the package 202. According to existing packaging technologies, where the package
has one pair of power and ground planes 314,316, the loop area results in about 30 picohenrys (pH)/square
of lateral inductance. Where the package has two pairs of power and ground planes 314,316 (as illustrated),
the total lateral inductance can be reduced to about 15 pH/square.
The capacitors" terminals 306,308 are also connected to the integrated circuit load (not shown)
through vias 318, thus enabling the capacitors 204 to provide bypassing capacitance to the integrated circuit.
Connection of the capacitors 204 to the load through the vias 318 results in some "vertical" inductance, also
referred to as "loop" inductance, to exist in the supply and return via loop between each capacitor 204 and
the integrated circuit load.
Figure 4 illustrates an electrical circuit that simulates the electrical characteristics of the capacitors
illustrated in Figures 1-3. For simplicity, no parasitic resistances of the capacitors are shown in Figure 4.
The circuit shows a die load 402, which may require bypassing capacitance in order to function properly.
Some of the bypassing capacitance can be supplied by capacitance, modeled by capacitor 404, located on thi
die. Other capacitance, however, must be provided off chip, as modeled by off-chip capacitors 406. The
off-chip capacitors 406 could be, for example, the DSCs 106, LSCs 108, and/or ECCs 110 illustrated in
Figure 1.
As described previously, lateral inductance, modeled by inductors 408, exists between capacitors
406. In addition, vertical loop inductance, partially modeled by inductor 410, exists between capacitors 406
and die load 402. For simplicity, a vertical loop inductance component for each capacitor is not shown.
Because lateral and vertical inductances tend to slow the response time of off-chip capacitors 406, i
is desirable to minimize the magnitudes of these inductances. For LSCs and DSCs, vertical loop inductance
can be reduced by using capacitors with interdigital contacts. In addition, vertical loop inductance issues cai
be addressed by placing off-chip capacitors 406 as electrically close as possible to the die load, such as by
using ECCs that may be closer to the load than surface mounted capacitors. Similarly, lateral inductance
issues can be addressed by placing adjacent capacitors, close to each other. For example, adjacent capacitors
may be attached to adjacent pads on the package.
Although these solutions are sufficient in certain cases, as the frequencies and edge rates of
electronic devices continue to advance, there is an increasing need for higher levels of bypassing
capacitance. In addition, there is a need for capacitance solutions that minimize the lateral inductance
present between LSCs, DSCs, and ECCs. Accordingly, there is a need in the art for alternative capacitance
solutions in the fabrication and design of electronic assemblies, such as integrated circuit packages.
Brief Description of the Accompanying Drawings
Figure 1 illustrates a cross-section of an integrated circuit package having die side, land side, and
embedded chip capacitors in accordance with the prior art;
Figure 2 illustrates a bottom view of an integrated circuit package having multiple LSCs, which are
electrically connected to pads on the bottom of the package, in accordance with the prior art;
Figure 3 illustrates a cross-sectional view of a portion of the integrated circuit package and LSCs of
Figure 2 along section lines 3-3;
Figure 4 illustrates an electrical circuit that simulates the electrical characteristics of the capacitors
illustrated in Figures 1-3;
Figure 5 illustrates a top or bottom view of a portion of an integrated circuit package having
multiple surface mounted capacitors, which are electrically connected to pads on the surface of the package,
in accordance with one embodiment of the present invention.
Figure 6 illustrates a cross-sectional view of a portion of the integrated circuit package and surface
mounted capacitors of Figure 5 along section lines 6-6;
Figure 7 illustrates a top or bottom view of a portion of an integrated circuit package having
multiple surface mounted capacitors, which are electrically connected to pads on the surface of the package,
in accordance with another embodiment of the present invention;
Figure 8 illustrates a cross-sectional view of a portion of the integrated circuit package and surface
mounted capacitors of Figure 7 along section lines 8-8;
Figure 9 illustrates a top or bottom view of a portion of an integrated circuit package having
multiple surface mounted capacitors, which are electrically connected to pads on the surface of the package,
in accordance with another embodiment of the present invention;
Figure 10 illustrates a top or bottom view of a portion of an integrated circuit package having
multiple surface mounted capacitors, which are electrically connected to pads on the surface of the package,
in accordance with another embodiment of the present invention;
Figure 11 illustrates a top or bottom view of a portion of an integrated circuit package having
multiple surface mounted capacitors, which are electrically connected to pads on the surface of the package,
in accordance with another embodiment of the present invention;
Figure 12 illustrates an interior, top or bottom view of an integrated circuit package having multiple
ECCs, in accordance with one embodiment of the present invention;
Figure 13 illustrates a cross-sectional view of a portion of the integrated circuit package and ECCs
/ of Figure 12 along section lines 13-13;
Figure 14 illustrates a flowchart of a method for manufacturing an electronic assembly having
laterally connected capacitors in accordance with one embodiment of the present invention;
Figure 15 illustrates an integrated circuit package, interposer, socket, and printed circuit board, each
of which could include one or more sets of laterally connected capacitors in accordance with various
embodiments of the present invention; and
Figure 16 illustrates an electronic system in accordance with one embodiment of the present
invention.
Detailed Description of the Invention
Various embodiments of the present invention provide off-chip capacitance at reduced lateral
inductance levels for bypassing, voltage dampening, and supplying charge. The various embodiments can
be used to reduce the lateral inductance present between LSCs, DSCs, ECCs or other discrete capacitor
configurations. In various embodiments, this is accomplished by using an existing feature inside discrete,
multi-layer capacitors. This feature, which is the extremely low lateral inductance inside these capacitors, is
exploited by electrically connecting the terminals of adjacent, discrete capacitors together, rather than
relying on electrical connections formed from conductive structures within or on the surface of a package.
These direct connections, referred to herein as "lateral connections," result in extremely low lateral
inductances between LSCs, DSCs, and ECCs. Basically, the lateral connections of the various embodiments
provide lateral current paths between the discrete capacitors. By utilizing lateral connections between the
numerous conductive planes within the discrete capacitors, the various embodiments provide a high-
frequency current redistribution network for the power delivery system. The effective redistribution of high-
frequency current results in substantially reduced system noise and a more effective usage of bypassing
capacitors. In addition, by reducing the system noise, the various embodiments can increase manufacturing
yields and decrease the number of bypassing capacitors needed, thus reducing costs.
Although the description of the various embodiments refers primarily to using discrete capacitors in
conjunction with an integrated circuit package, the various embodiments also could be used in conjunction
with other types of packages, ihterposers, printed circuit boards or other electronic circuit housings. In other
words, the various embodiments could be used in conjunction with various types of electronic assemblies,
and is not meant to be limited to use with integrated circuit packages. In addition, the various embodiments
could be used with a number of different types of packages and packaging technologies. For example, the
various embodiments could be used with organic or ceramic packages, and the packaging technologies with
which the embodiments could be used include but are not limited to. land grid array (e.g., organic LGA), pin
grid array (e.g., plastic PGA or flip chip PGA), ball grid array (e.g., _BGA, tape BGA, plastic BGA, flip
chip BGA or flip chip tape BGA), tape automated bonding, wire bonding, and beam lead.
Figure 5 illustrates a top or bottom view of a portion of an integrated circuit package 502 having
multiple surface mounted capacitors 504 (e.g., LSCs or DSCs), which are electrically connected to pads 506
on the surface of the package, in accordance with one embodiment of the present invention. Capacitors 504
could be, for example, ceramic chip capacitors, organic capacitors, integrated circuit capacitors or other

types of discrete capacitors.
Capacitors 504 include twelve terminals 508 distributed on all four sides. These terminals 508
provide electrical connections to conductive planes of an internal capacitor structure (not shown) within
capacitor 504. Going clockwise from the upper left terminal of each capacitor 504, the polarities of the
terminals typically alternate between positive and negative, as indicated by the alternating cross-hatched
patterns. In other words, the cross-hatching present on terminals 508 is intended to indicate that terminals
508 are connected either to positive or negative interior planes within the capacitors 504, and also that the
terminals 508 are connected, in an alternating manner, to power and ground planes (not shown) within the
package 502.
As will be exemplified below, capacitors 504 having more or fewer terminals distributed on more
or fewer sides also could be used in conjunction with various embodiments. In addition, the polarities of the
terminals need not strictly alternate between adjacent terminals. Although only four capacitors 504 are
shown in the figure, more or fewer capacitors could be used as well. In some cases, thirty or more capacitors
could be used to supply off-chip capacitance to a die.
As the figure indicates, some of the terminals 510 of each capacitor 504 have direct, lateral
connections 512 to some of the terminals 510 of adjacent capacitors. Each lateral connection 512 is between
adjacent terminals 510 having the same polarity. Accordingly, a positive terminal 510 of a first discrete
capacitor would be laterally connected to a positive terminal 510 of a second, adjacent discrete capacitor.
This represents a significant distinction between the embodiments of the present invention and the prior art,
where no such direct, lateral connections are present.
Terminals of a capacitor 504 could be laterally connected to terminals of one, two or more adjacent
capacitors. Accordingly, a capacitor 504 could be laterally connected to other capacitors on one, two or
more sides. For example, terminals of each capacitor shown in Figure 5 are connected on two sides. In
addition, although it is not shown in Figure 5, the terminals on a single side of a particular capacitor could be
connected to the terminals on one or multiple adjacent capacitors.
Figure 6 illustrates a cross-sectional vjew of a portion of the integrated circuit package 502 and
surface mounted capacitors 504 of Figure 5 along section lines 6-6. When capacitors 504 are multi-layer
capacitors, as shown, each capacitor 504 includes multiple interior planes 602,604 of conductive material,
separated by layers of dielectric material; Although only six planes are shown, numerous planes are usually
present (e.g., tens or hundreds of planes).
Typically, conductive planes 602,604 are configured so that alternating planes connect to
alternating terminals 606,608 substantially located on the sides of the capacitor. This enables terminals 606,
608 and planes 602,604 to be connected, in an alternating manner, to pads 610,612 on the package body
502, as described in conjunction with Figure 5. Pads 610,612, in turn, connect to either power or ground
planes 614,616 within the package body 502 through plated or filled vias 618. For ease of description,
Figures 6, 8 and 13 do not completely illustrate all of the various conducting and non-conducting layers that
a package may have. Layers above and/or below planes 614,616 may also exist.
In one embodiment, at least one terminal 608 of each capacitor 504 has a direct, lateral connection
620 to a terminal 608 of an adjacent capacitor 504, where the lateral connection 620 is between adjacent
terminals 608 having the same polarity. In one embodiment, the lateral connection 620 spans an elongated
pad 610, which covers substantially aiJ of the distance between what would otherwise be two, adjacent
standard sized pads (e.g., standard sized pads 612). This enables capacitors 504 to be placed on the package
with the equivalent of a standard pad pitch of distance between them. Shorter or longer elongated pads
could be used as well.
In one embodiment, the lateral connection 620 is achieved using a conductive material 620 between
the adjacent terminals 608. This conductive material 620 could be, in various embodiments, solder or a
cured, conductive paste or adhesive, for example. The conductive material 620 could also be used to "
connect the capacitors 504 to the package pads 610,612, or separate applications of conductive material
could be used to achieve the capacitor-to-pad and capacitor-to-capacitor connections.
Because the capacitors 504 are interconnected directly through lateral connections 620, and are not
interconnected only through conductive structures within the package (e.g., combinations of pads, vias, and
power or ground planes), the lateral inductance between the capacitors 504 is substantially reduced. In other
words, the lateral current between capacitors 504 is carried substantially over the lateral connection 620,
rather than over a conductive loop having a loop area that is bounded by various conductive structures of the
package. Accordingly, the lateral connections have been shown to reduce the lateral inductance to fractions
of picohenrys (e.g., 0.03 pH/square or less) from the tens of picohenrys that result from using prior art
technologies. By utilizing lateral connections 620 between the conductive planes 602,604 within the
discrete capacitors 504, a high-frequency current redistribution network for the power delivery system is
provided.
Figure 7 illustrates a top or bottom view of a portion of an integrated circuit package 702 having
multiple surface mounted capacitors 704 (e.g., LSCs or DSCs), which are electrically connected to pads 706
on the surface of the package, in accordance with another embodiment of the present invention. Essentially,
the embodiment illustrated in Figure 7 is similar to the embodiment illustrated in Figure 5, except that little
or no physical distance exists between adjacent capacitors 704. In this embodiment, adjacent capacitors 704
are in physical contact with each other or have a negligible distance between each other.
Figure 8 illustrates a cross-sectional view of a portion of the integrated circuit package 702 and
surface mounted capacitors 704 of Figure 7 along section lines 8-8. The embodiment illustrated in Figure 8
is similar to the embodiment illustrated in Figure .6, except that little or no distance exists between adjacent
terminals 802 of capacitors 704. Accordingly, the lateral connection between terminals 802 is accomplished
by physical contact, in one embodiment. In the embodiment illustrated, both capacitors 704 can be
connected to a standard sized pad 708 on the package 702.
The lateral connection is further achieved, in one embodiment, using a conductive material 804
between the adjacent terminals 802. This conductive material 804 could be, in various embodiments, solder
or a cured, conductive paste or adhesive, for example. As with the embodiment illustrated in Figure 6, the
conductive material 804 could also be used to connect the capacitors 704 to the package pads 708, or
separate applications of conductive material could be used to achieve the capacitor-to-pad and capacitor-to-
capacitor connections.
Figure 9 illustrates a top or bottom view of a portion of an integrated circuit package 902 having
multiple surface mounted capacitors 904 (e.g., LSCs or DSCs), which are electrically connected to pads 906
on the surface of the package, in accordance with another embodiment of the present invention. Capacitors
904 include eight terminals 908 distributed on two sides. Lateral connections 910 are present between
adjacent, same-polarity terminals of adjacent capacitors 904. Because capacitors 904 have terminals 908 on
only two sides, however, these lateral connections 910 are present on only two sides. Figure 9 is intended to
illustrate that lateral connections can be made between capacitors having various numbers of terminals on
various numbers of sides. The embodiment shown in Figure 9 shows the capacitors 904 as being physically
separated from each other. In other embodiments, capacitors 904 could be in physical contact with each
other, or have a negligible distance between each other, as was illustrated in Figures 7 and 8.
As another example, Figure 10 illustrates atop or bottom view of a portion of an integrated circuit
package 1002 having multiple surface mounted capacitors 1004 (e.g., LSCs or DSCs), which are electrically
connected to pads 1006 on the surface of the package, in accordance with another embodiment of the present
invention. In this embodiment, capacitors 1004 are two-terminal, discrete capacitors. Commonly, although
not necessarily, these types of capacitors include terminals 1008 that extend the entire length of the sides of
the capacitor 1004. Because terminals 1008 are longer than many capacitors with more terminals, elongated
lateral connections 1010 are present between same-polarity terminals of adjacent capacitors 1004. The
elongated lateral connections 1010 are made to span enlarged pads (not shown) on the package surface, in
one embodiment. These enlarged pads have a shape that facilitates the formation of lateral connections 1010
out of a conductive material, such as solder or a cured, conductive paste or adhesive, for example. The
embodiment shown in Figure 10 shows the capacitors 1004 as being physically separated from each other.
In other embodiments, capacitors 1004 could be in physical contact with each other, or have a negligible
distance between each other, as was illustrated in Figures 7 and 8.
Figure 11 illustrates a top or bottom view of a portion of an integrated circuit package 1102 having
multiple surface mounted capacitors 1104,1112,1114,1116 (e.g., LSCs or DSCs), which are electrically
connected to pads 1106 on the surface of the package, in accordance with another embodiment of the present
invention. The embodiment illustrated in Figure 11 is similar to the embodiment illustrated in Figure 10,
except that adjacent terminals 1108 on adjacent capacitors not only have lateral connections 1110 in the
vertical direction (e.g., between capacitors 1112 and 1114), but the terminals 1108 also have lateral
connections 1110 in the horizontal direction (e.g., between capacitors 1114 and 1116). The enlarged lateral
connections 1110 are made to span enlarged pads (not shown) on the package surface, in one embodiment.
Figure 11 illustrates that, when a particular terminal contacts more than one side of the capacitor, lateral
connections to the terminal can be made on more than one side of the capacitor, as shown. The embodiment
shown in Figure 11 shows the capacitors 1104, 1112, 1114,1116 as being physically separated from each
other. In other embodiments, capacitors 1104,1112,1114,1116 could be in physical contact with each
other, or have a negligible distance between each other, as was illustrated in Figures 7 and 8.
Figure 12 illustrates an interior, top or bottom view of an integrated circuit package 1202 having
multiple embedded chip capacitors 1204 (ECCs), in accordance with one embodiment of the present
invention. The embodiment illustrated in Figure 12 is similar to the embodiment illustrated in Figure 5,
except that the ECCs are embedded within the package 1202, and the terminals 1206 of the ECCs 1204 are
connected to conductive structures (e.g., traces and/or vias) within the package 1202, rather than to pads on
the surface of the package. The lateral connections 1208 between terminals 1206 of adjacent ECCs 1204 are
made in a similar manner to those discussed in conjunction with Figures 5 and 6.
Figure 13 illustrates a cross-sectional view of a portion of the integrated circuit package 1202 and
ECCs 1204 of Figure 12 along section lines 13-13. Similar to the surface mount capacitors described
previously, when capacitors 1204 are multy fayer capacitor, as shown, each capacitor 1204 includes
multiple interior planes 1302, 1304 of conductive material, separated by layers of dielectric material.
Typically, conductive planes 1302,1304 are configured so that alternating planes connect to
alternating terminals 1306,1308 around the capacitor. This enables terminals 1306,1308 and planes 1302,
1304 to be connected, in an alternating manner, to conductive structures within the package body. These
conductive structures can be vias 1310, such as illustrated in Figure 13, or they can be conductive traces or
planes (not shown) within the package. The conductive structures, in turn, connect to either power or
ground planes 1312,1314 within the package body. In the embodiment shown, vias 1310 make contact with
terminals 1306, 1308 from the top of capacitors 1204. In other embodiments, one or more vias could make
contact with terminals 1306,1308 from the bottom of capacitors 1204.
Figure 13 does not completely illustrate the various conducting and non-conducting layers of
package 1202, for ease of description. In an actual package design, one or more additional conducting
and/or non-conducting layers could exist above, below, or in parallel with capacitors 1204. In order to
minimize the loop inductance between capacitors 1204 and a die load, it may be desirable to embed
capacitors 1204 as close to the top surface of the package 1202 as possible, although this is not essential.
The capacitors could be embedded in one or multiple layers of a single package.
In one embodiment, at least one terminal 1306 of each capacitor 1204 has a direct, lateral
connection 1316 to a terminal 1306 of an adjacent capacitor 1204, where the lateral connection 1316 is
between adjacent terminals 1306 having the same polarity. The lateral connection 1316 spans the distance
between the adjacent terminals 1306. In various other embodiments, the adjacent terminals 1306 can be in
physical contact (e.g., with little or no distance between them), or they can be separated by some non-
negligible distance.
In one embodiment, the lateral connection 1316 is achieved using a conductive material 1316
between the adjacent terminals 1306. This conductive material_1316 could be, in various embodiments,
solder or a cured, conductive paste or adhesive, for example. The conductive material 1316 could also be
used to connect the capacitors 1304 to the package"s internal conductive structures, or separate applications
of conductive material could be used to achieve the capacitor-to-package and capacitor-to-capacitor
connections.
In various embodiments, each capacitor 504, 704, 904,1004, 1104, and 1204, illustrated in Figures
5-13 could be a ceramic capacitor, aluminum oxide capacitor, organic capacitor or a capacitor made with
many other technologies, as would be obvious to one of skill in the art based on the description herein. In
addition, the actual and relative dimensions of capacitors 504,704,904,1004,1104, and 1204 could vary
widely, depending on design and manufacturing constraints or other factors. In addition, capacitors 504,
704,904,1004,1104, and 1204 need not necessarily be rectangular in shape, as they could assume a number
of different shapes (e.g., square or multi-sided).
Figure 14 illustrates a flowchart of a method for manufacturing an electronic assembly having
laterally connected capacitors in accordance with one embodiment of the present invention. The method
begins, in block 1402, by fabricating one or more layers of an electronic housing. The electronic housing
could be, for example, an integrated circuit package, other type of package, interposer, printed circuit (PC)
board, or other type of electronics cirouit package. The details regarding fabricating the housing layer(s)
depend entirely on the type of packaging technology used, and a discussion of the various packaging
technology fabrication methods are outside of the scope of this invention. Fabrication of the electronic
housing layers results in a rigid structure with conductive pads on its surface and/or other exterior or interior
conductive structures.
In block 1404, two or more discrete capacitors are laterally attached to the electronic housing.
Where the discrete capacitors are LSCs or DSCs, lateral attachment involves attaching the capacitors to pads
on the surface of the electronic housing, so that one or more terminals of one or more adjacent capacitors are
attached together with a lateral connection (e.g., connection 620, Figure 6). Attachment of the capacitors to
the housing and to each other can be done in separate processes, or can be done simultaneously. For
example, the discrete capacitors can first be surface mounted to the housing pads, and then the adjacent
capacitors" terminals can be laterally attached in a separate process. Alternatively, the surface mounting and
lateral attachment can be performed simultaneously, for example, by soldering the pads and adjacent
terminals together at the same time. Alternatively, a cured, conductive paste or adhesive could be used to
provide the capacitor-to-pad and/or lateral connections.
Where the discrete capacitors are ECCs, the capacitors would be placed on the top layer of the
partial housing or within depressions within the housing. The ECCs would then be laterally attached to each
other and/or to conductive structures within the housing using one or several processes.
After laterally attaching the discrete capacitors, the housing fabrication is completed, if necessary,
in block 1406. In the case of ECCs, this may include building up one or more additional layers of patterned
conductive and dielectric materials over the ECCs, including the formation of vias and/or other conductive
structures. The process then ends.
As described previously, laterally connected capacitors, such as those described in the various
embodiments above, can be included on or within an integrated circuit package, interposer, socket, PC
board, and/or other types of electronic circuit housing. Figure 15 illustrates an integrated circuit package
1504, interposer 1506, socket 1508, and PC board 1510 each of which could include two or more laterally
connected capacitors in accordance with various embodiments of the present invention.
Starting from the top of Figure 15, an integrated circuit 1502 is housed by integrated circuit
package 1504. Integrated circuit 1502 contains one or more circuits, which are electrically connected to
integrated circuit package 1504 by connectors (not shown).
Integrated circuit 1502 could be any of a number of types of integrated circuits. In one embodiment
of the present invention, integrated circuit 1502 is a microprocessor. In other embodiments., integrated
circuit 1502 could be a memory device, application specific integrated circuit, digital signal processor, or
another type of divice. In the example shown, integrated circuit 1502 is a "flips chip" type of integrated
circuit, meaning that the input/output terminations on the chip can occur at any point on its surface. After
the chip has been readied for attachment to integrated circuit package 1504, it is flipped over and attached,
via solder bumps or balls to matching pads on the top surface of integrated circuit package 1504.
Alternatively, integrated circuit 1502 could be wire bonded, where input/output terminations are connected
to integrated circuit package 1504 using bond wires to pads on the top surface of integrated circuit package
1504, or otherwise connected to package 1504.
One or more of the circuits within integrated circuit 1502 acts as a load, which may require
bypassing capacitance for noise or radiation suppression, and/or voltage dampening. Some of this
capacitance is provided, in one embodiment of the present invention, by laterally connected DSCs 1512,
LSCs 1514, and/or ECCs 1516, which are surface mounted on and/or embedded within package 1504. In
this manner, one or more levels of additional capacitance are provided to integrated circuit 1502. In other
embodiments, laterally connected capacitors 1518 are surface mounted on and/or embedded within
interposer 1506, socket 1508, and/or PC board 1510.
Integrated circuit package 1504 is coupled to interposer 1506 using solder connections, such as ball
grid array connections, for example. In another embodiment, integrated circuit package 1504 could be
electrically and physically connected to interposer 1506 using a pinned or other type of connection.
Interposer 1506 is coupled to PC board 1510 through a socket 1508 on PC board 1510. In the
example shown, interposer 1506 includes pins, which mate with complementary pin holes in socket 1508.
Alternatively, interposer 1506 could be electrically and physically connected to PC board 1510 using solder
connections, such as ball grid array connections, for example. In still another alternate embodiment,
integrated circuit package 1504 could be connected directly to socket 1508 and/or PC board 1510, without
using an interposer. In such an embodiment, integrated circuit package 1504 and PC board 1510 couJd be
electrically and physically connected using ball grid array or pinned connections. Other ways of connecting
integrated circuit package 1504 and PC board 1510 could also be used in other embodiments.
PC board 1510 could be, for example, a motherboard of a computer or other electronic system. As
such, it acts as a vehicle to supply power, ground, and signals to integrated circuit 1502. These power,
ground, and other signals are supplied through traces or planes (not shown) on or within PC board 1510,
socket 1508, interposer 1506, and integrated circuit package 1504.
The configurations described above in conjunction with various embodiments could form part of an
electronic system. Figure 16 illustrates an electronic system in accordance with one embodiment of the
present invention. The system shown in Figure 16 could be, for example, a computer, a wireless or wired
communication device (e.g., telephone, modem, cell phone, pager, radio, etc.), a television, a monitor, or
virtually any other type of electronic system that could benefit from the use of laterally connected capacitors.
The electronic system includes circuit 1602, housing 1604, PC board 1606, and power supply 1608.
Housing 1604 and/or PC board 1606 include two or more laterally connected capacitors surface mounted on
or embedded within them, in accordance with various embodiments of the present invention.
Conclusion
Various embodiments of an electronic assembly with laterally connected capacitors and methods of
fabricating that assembly have been described, along with a description of the incorporation of the assembly
within an electronic system. The various embodiments can be used to reduce the lateral inductance present
between LSCs, DSCs, ECCs or other discrete capacitor configurations. In various embodiments, the
extremely low lateral inductance inside multi-layer capacitors is exploited by electrically connecting the
terminals of adjacent, discrete capacitors together, rather than relying on electrical connections formed from
conductive structures within or on the surface of the package. These lateral connections result in extremely
low lateral inductances between LSCs, DSCs, and ECCs. By utilizing lateral connections between the
numerous conductive planes within the discrete capacitors, the various embodiments provide a high-
frequency current redistribution network for the power delivery system.
While the foregoing examples of dimensions and ranges are considered typical, the various
embodiments of the invention are not limited to such dimensions or ranges. It is recognized that the trend
within industry is to generally reduce device dimensions for the associated cost and performance benefits.
In the foregoing detailed description, reference is made to the accompanying drawings, which form
a part hereof, and in which are shown by way of illustration specific embodiments in which the invention
may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to
practice the invention.
It will be appreciated by those of ordinary skill in the art that any arrangement, which is calculated
to achieve the same purpose, may be substituted for the specific embodiment shown. For example, although
some of the figures show four discrete capacitors arranged in a square pattern, more or fewer capacitors
could be used, and they could be arranged in other pattern configurations, including linear, ring or irregularly
shaped configurations.
The various embodiments have been described in the context of providing excess, off-chip
capacitance to a die. One of ordinary skill in the art would understand, based on the description herein, that
the method and apparatus of the present invention could also be applied in many other applications where a
capacitor configuration having a low lateral inductance is desired. Therefore, all such applications are
intended to fall within the spirit and scope of the present invention.
This application is intended to cover any adaptations or variations of the present invention. The
foregoing detailed description is, therefore, not to be taken in a limiting sense, and it will be readily
understood by those skilled in the art that various other changes in the details, materials, and arrangements of
the parts and steps, which have been described and illustrated in order to explain the nature of this invention,
may be made without departing from the spirit and scope of the invention as expressed in the adjoining
claims.
1. An electronic assembly, such as herein described comprising :
a first discrete capacitor attached to a housing, the first discrete capacitor having
multiple first interior planes, wherein a set of the multiple first interior planes electrically
connects to a first conductive terminal on a side of the first discrete capacitor; and
a second discrete capacitor attached to the housing, the second discrete capacitor
having multiple second interior planes, wherein a set of the multiple second interior planes
electrically connects to a second conductive terminal on a side of the second discrete
capacitor, and wherein the second conductive terminal is laterally attached to the first
conductive terminal.
2. The electronic assembly as claimed in claim 1, wherein there are provided one or
more additional discrete capacitors having one or more additional terminals that are directly
attached to one or more terminals of the first discrete capacitor, the second discrete
capacitor, or other capacitors.
3. The electronic assembly as claimed in claim 2, wherein there is provided a third
discrete capacitor, wherein a third conductive terminal on a side of the third discrete capacitor
is attached to a fourth conductive terminal on a second side of the first discrete capacitor.
4. The electronic assembly as claimed in claim 1, wherein the first conductive terminal
and the second conductive terminal are attached by physical contact.
5. The electronic assembly as claimed in claim 1, wherein the first conductive terminal
and the second conductive terminal are attached by a conductive material between the first
conductive terminal and the second conductfve terminal.
6. The electronic assembly as claimed in claim 5, wherein the first discrete capacitor and
the second discrete capacitor are surface mounted capacitors, and the first conductive
terminal and the second conductive terminal are attached together by the conductive
material, which spans a length of a pad on a surface of the housing.
7. The electronic assembly as claimed in claim 1, wherein the housing is an integrated
circuit package, and the first discrete capacitor and the second discrete capacitor are
mounted on a land side of the integrated circuit package.
8. The electronic assembly as claimed in claim 1, wherein the housing is an integrated
circuit package, and the first discrete capacitor and the second discrete capacitor are
mounted on a die side of the integrated circuit package.
9. The electronic assembly as claimed in claim 1, wherein the housing is an integrated
circuit package, and the first discrete capacitor and the second discrete capacitor are
embedded within the integrated circuit package.
10. The electronic assembly as claimed in claim 1, wherein the first discrete capacitor and
the second discrete capacitor are ceramic chip capacitors.
11. The electronic assembly as claimed in claim 1, wherein the first discrete capacitor and
the second discrete capacitor are organic capacitors.
12. The electronic assembly as claimed in claim 1, wherein there is provided a conductive
material between the first conductive terminal and the second conductive terminal.
13. The electronic assembly as claimed in claim 12, wherein the conductive material is a
solder material.
14. The electronic assembly as claimed in claim 12, wherein the conductive material is a
cured, conductive paste.
15. The electronic assembly as claimed in claim 1, wherein there is provided the housing,
wherein the housing is an integrated circuit package.
16. A method for manufacturing an electronic assembly, such as herein described,
comprising :
attaching a first discrete capacitor to an electronic housing, wherein the first discrete
capacitor has multiple first interior planes, and a set of the multiple first interior planes
electrically connects to a first conductive terminal on a side of the first discrete capacitor;
attaching a second discrete capacitor to the electronic housing, wherein the second
discrete capacitor has multiple second interior planes, and a set of the multiple second
interior planes electrically connects to a second conductive terminal on a side of the second
discrete capacitor; and
laterally attaching the second conductive terminal to the first conductive terminal.
17. The method as claimed in claim 16, wherein the first discrete capacitor and the second
discrete capacitor are attached to the electronic housing by surface mounting the first
discrete capacitor and the second discrete capacitor to the electronic housing.
18. The method as claimed in claim 16, wherein the first discrete capacitor and the second
discrete capacitor are attached to the electronic housing by embedding the first discrete
capacitor and the second discrete capacitor within the electronic housing.
19. The method as claimed in claim 16, wherein one or more additional capacitors is / are
laterally attached to the first discrete capacitor or the second discrete capacitor.
20. The method as claimed in claim 16, wherein laterally attaching the second conductive
terminal to the first conductive terminal comprises soldering the second conductive terminal
and the first conductive terminal together.
21. The method as claimed in claim 16, wherein laterally attaching the second conductive
terminal comprises depositing a conductive paste in contact with the first conductive terminal
and the second conductive terminal and curing the conductive paste.
22. An electronic housing comprising :
one or more layers of patterened, conductive material;
a first discrete capacitor attached to the one or more layers, the first discrete capacitor
having multiple first interior planes, wherein a set of the multiple first interior planes
electrically connects to a first conductive terminal on a side of the first discrete capacitor; and
a second discrete capacitor attached to the one or more layers, the second discrete
capacitor having multiple second interior planes, wherein a set of the multiple second interior
planes electrically connects to a second conductive terminal on a side of the second discrete
capacitor ; and wherein the second conductive terminal is laterally attached to the first
conductive terminal.
23. The electronic housing as claimed in claim 22, wherein the first discrete capacitor and
the second discrete capacitor are embedded within the electronic housing.
24. The electronic housing as claimed in claim 22, wherein the first discrete capacitor and
the second discrete capacitor are mounted on a surface of the housing.
25. The electronic housing as claimed in claim 22, wherein the electronic housing is an
integrated circuit package.
26. An electronic system comprising :
a housing;
a first discrete capacitor attached to the housing, the first discrete capacitor having
multiple first interior planes, wherein a set of the multiple first interior planes electrically
connects to a first conductive terminal on a side of the first discrete capacitor; and
a second discrete capacitor attached to the housing, the second discrete capacitor
having multiple second interior planes, wherein a set of the multiple second interior planes
electrically connects to a second conductive terminal on a side of the second discrete
capacitor ; and wherein the second conductive terminal is laterally attached to the first
conductive terminal.
27. The electronic housing as claimed in claim 26, wherein the first discrete capacitor and
the second discrete capacitor are embedded within the housing.
28. The electronic housing as claimed in claim 26, wherein the first discrete capacitor and
the second discrete capacitor are mounted on a surface of the housing.
29. The electronic housing as claimed in claim 26, wherein the housing is an integrated
circuit package.
An electronic assembly includes multiple discrete capacitors (504, Figure 5), which are surface mounted to or embedded
within an electronic housing, such as an integrated circuit package (1504, Figure 15). One or more side terminals (510) of
adjacent capacitors are electrically connected through lateral connections (512, 620, Figures 5, 6). These lateral connections provide
an extremely low lateral inductance current path between the discrete capacitors.

Documents:

01604-kolnp-2003-abstract.pdf

01604-kolnp-2003-claims.pdf

01604-kolnp-2003-correspondence.pdf

01604-kolnp-2003-description (complete).pdf

01604-kolnp-2003-drawings.pdf

01604-kolnp-2003-form 1.pdf

01604-kolnp-2003-form 18.pdf

01604-kolnp-2003-form 3.pdf

01604-kolnp-2003-form 5.pdf

01604-kolnp-2003-gpa.pdf

01604-kolnp-2003-letter patent.pdf

01604-kolnp-2003-reply first examination report.pdf


Patent Number 216307
Indian Patent Application Number 01604/KOLNP/2003
PG Journal Number 11/2008
Publication Date 14-Mar-2008
Grant Date 12-Mar-2008
Date of Filing 10-Dec-2003
Name of Patentee INTEL CORPORATION.
Applicant Address 2200 MISSION COLLEGE BOULEVARD, SANTA CLARA CA 95052 USA.
Inventors:
# Inventor's Name Inventor's Address
1 LI YYAN-LIANG 1422 W. HOPPI DRIVE, CHANDLER AZ 85224 USA.
2 CHUNG CHEE-YEE 5141 WEST SHANNON STREET CHANDLER USA.
PCT International Classification Number D 04 B 15/48
PCT International Application Number PCT/US02/18740
PCT International Filing date 2002-06-13
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 09/881,342 2001-06-14 U.S.A.