U.S. patent application number 12/552321 was filed with the patent office on 2011-03-03 for integrated voltage regulator with embedded passive device(s).
This patent application is currently assigned to QUALCOMM INCORPORATED. Invention is credited to Lew G. Chua-Eoan, Yuancheng Christopher Pan, Junmou Zhang, Zhi Zhu.
Application Number | 20110050334 12/552321 |
Document ID | / |
Family ID | 43037102 |
Filed Date | 2011-03-03 |
United States Patent
Application |
20110050334 |
Kind Code |
A1 |
Pan; Yuancheng Christopher ;
et al. |
March 3, 2011 |
Integrated Voltage Regulator with Embedded Passive Device(s)
Abstract
A semiconductor packaging system has a packaging substrate into
which inductors and/or capacitors are partially or completely
embedded. An active portion of a voltage regulator is mounted on
the packaging substrate and supplies regulated voltage to a die
also mounted on the packaging substrate. Alternatively, the active
portion of the voltage regulator is integrated into the die the
voltage regulator supplies voltage to. The voltage regulator
cooperates with the inductors and/or capacitors to supply voltage
to the die. The inductors may be through vias in the packaging
substrate. For additional inductance, through vias in a printed
circuit board on which the packaging substrate is mounted may
couple to the through vias in the packaging substrate.
Inventors: |
Pan; Yuancheng Christopher;
(San Diego, CA) ; Chua-Eoan; Lew G.; (Carlsbad,
CA) ; Zhu; Zhi; (San Diego, CA) ; Zhang;
Junmou; (San Diego, CA) |
Assignee: |
QUALCOMM INCORPORATED
San Diego
CA
|
Family ID: |
43037102 |
Appl. No.: |
12/552321 |
Filed: |
September 2, 2009 |
Current U.S.
Class: |
327/564 ;
327/540 |
Current CPC
Class: |
H01L 25/16 20130101;
H01L 2924/15192 20130101; H01L 25/0652 20130101; H05K 1/185
20130101; H01L 23/645 20130101; Y10T 29/4913 20150115; H05K 1/0262
20130101; H05K 1/141 20130101; H01L 2924/15311 20130101; H02M 3/00
20130101; H01L 2924/15174 20130101; H01L 2224/16225 20130101; H01L
23/642 20130101 |
Class at
Publication: |
327/564 ;
327/540 |
International
Class: |
H01L 25/00 20060101
H01L025/00 |
Claims
1. A voltage regulator, comprising: a passive portion at least
partially embedded in a packaging substrate; and an active portion
fabricated in a die coupled to the passive portion.
2. The voltage regulator of claim 1, in which the passive portion
comprises at least one capacitor.
3. The voltage regulator of claim 2, in which the at least one
capacitor is an embedded die.
4. The voltage regulator of claim 1, in which the die is mounted on
the packaging substrate.
5. The voltage regulator of claim 4, further comprising: a second
die mounted on the packaging substrate to which the active portion
supplies voltage.
6. The voltage regulator of claim 1, in which the passive portion
comprises at least one inductor.
7. The voltage regulator of claim 6, in which the passive portion
further comprises at least one capacitor.
8. The voltage regulator of claim 6, in which the at least one
inductor comprises a first plurality of through vias in the
packaging substrate.
9. The voltage regulator of claim 8, in which the at least one
inductor further comprises a second plurality of through vias in a
printed circuit board that couples to the first plurality of
through vias in the packaging substrate.
10. The voltage regulator of claim 9, further comprising a coil
that couples the second plurality of through vias.
11. The voltage regulator of claim 10, in which the coil comprises
an inductor coil mounted on a back side of the printed circuit
board, the inductor coil wrapping a core.
12. The voltage regulator of claim 1, integrated into a device
selected from a group consisting of a music player, a video player,
an entertainment unit, a navigation device, a communications
device, a personal digital assistant (PDA), a fixed location data
unit, and a computer.
13. A method of supplying voltage to a die mounted on a packaging
substrate, the method comprising: mounting an active portion of a
voltage regulator on the packaging substrate; and coupling the
active portion of the voltage regulator to at least one passive
component at least partially embedded in the packaging substrate;
and coupling the die to the at least one passive component.
14. The method of claim 13, in which mounting the active portion of
the voltage regulator comprises mounting the die on the packaging
substrate, the die including the active portion of the voltage
regulator.
15. The method of claim 13, in which coupling the active portion of
the voltage regulator to at least one passive component comprises
coupling the active portion of the voltage regulator to at least
one through via that provides inductance to the active portion of
the voltage regulator.
16. The method of claim 13, in which coupling the active portion of
the voltage regulator to at least one passive component comprises:
coupling the active portion of the voltage regulator to at least
one capacitor at least partially embedded in the packaging
substrate; and coupling the active portion of the voltage regulator
to at least one inductor at least partially embedded in the
packaging substrate.
17. A method of supplying power to a die, the method comprising:
providing a supply voltage to an active portion of a voltage
regulator mounted on a packaging substrate mounted on a printed
circuit board; passing the supply voltage from the active portion
of the voltage regulator to at least one inductor at least
partially embedded in the packaging substrate; passing the supply
voltage from the at least one inductor to at least one capacitor at
least partially embedded in the packaging substrate; and passing
the supply voltage from the at least one capacitor to the die.
18. The method of claim 17, in which passing the supply voltage to
at least one inductor comprises passing the supply voltage to a
first plurality of through vias in the packaging substrate.
19. The method of claim 18, further comprising: passing the supply
voltage from the first plurality of through vias in the packaging
substrate to a second plurality of through vias in the printed
circuit board; and passing the supply voltage from the second
plurality of through vias in the printed circuit board to the first
plurality of through vias in the packaging substrate.
20. A semiconductor packaging system, comprising: a packaging
substrate into which at least one means for storing energy is at
least partially embedded; and means for regulating voltage mounted
on the packaging substrate and cooperating with the energy storing
means.
21. The semiconductor packaging system of claim 20, further
comprising: a first die mounted on the packaging substrate into
which the voltage regulating means is integrated; and a second die
mounted on the packaging substrate, the second die receiving
regulated voltage from the voltage regulating means.
22. The semiconductor packaging system of claim 20, in which the
energy storing means stores at least one of magnetic energy and
electric energy.
Description
TECHNICAL FIELD
[0001] The present disclosure generally relates to integrated
circuits (ICs). More specifically, the present disclosure relates
to manufacturing integrated circuits.
BACKGROUND
[0002] Integrated circuits (ICs) are fabricated on wafers.
Commonly, these wafers are semiconductor materials, such as
silicon, and singulated to form individual dies. Through efforts of
research and development, the size of the transistors making up the
ICs has decreased to 45 nm and will soon decrease to 32 nm. As
transistor size decreases, the supply voltage to the transistors
decreases. The supply voltage is conventionally smaller than wall
voltages available in most countries or battery voltages used in
portable devices. For example, an IC may operate at 1.25 Volts
whereas the wall voltage is 120V or 240V. In a portable device,
such as cellular phone, the battery voltage may range from 6V at
full charge to 3V at near empty charge.
[0003] A semiconductor die may be coupled to a voltage regulator
that converts available voltages at wall outlets or batteries to
lower voltages used by the die. The voltage regulator ensures a
constant voltage supply is provided to the die. This is an
important function, because the ability of transistors to tolerate
voltages under or over the target voltage is small. Only tenths of
a volt lower may create erratic results in the die; only tenths of
a volt higher may damage the die.
[0004] Dies are mounted on a packaging substrate, and the packaging
substrate is mounted on a printed circuit board (PCB) approximately
1-2 mm thick during assembly. Conventionally, the voltage regulator
is located on the PCB with the die to which the voltage regulator
supplies voltage. Placing the voltage regulator on the PCB separate
from the die results in a voltage drop between the voltage
regulator and the die that the voltage regulator supplies. For
example, at a supply voltage of 1.125 Volts, a voltage drop of
0.100V may occur between the voltage regulator and the die as the
voltage passes through the PCB, packaging substrate, and die. As
the supply voltage decreases with shrinking transistor size, the
voltage drop becomes a significant fraction of the supply voltage.
Additionally, placing the voltage regulator on the PCB requires the
use of pins on the die to allow the die to communicate with the
voltage regulator. The die may send commands to the voltage
regulator such as sleep or wake-up for scaling up or scaling down
the voltage supply. The additional pins consume space on the die
that could otherwise be eliminated.
[0005] Reducing the voltage drop from the voltage regulator to the
die improves performance of the die. Maximum frequency of a die
scales proportionally with supply voltage. For example, eliminating
a voltage drop of 0.100V may increase a maximum frequency
(f.sub.max) of the die by 100 MHz. Alternatively, if the voltage
drop is reduced and maximum frequency not increased, power
consumption in the die is reduced. Power consumption is
proportional to capacitance multiplied by a square of the supply
voltage. Thus, reducing the supply voltage may result in
significant power savings.
[0006] Further, conventional voltage regulators have slow response
times due to the distance between the voltage regulator and the
die. In the event the current transients are too fast for the
voltage regulator to respond, decoupling capacitors provide
additional power to the die. Voltage regulators located on the PCB
often have response times in the microsecond range. Thus, large
decoupling capacitors are placed on the packaging substrate to
compensate for slow response times. The large decoupling capacitors
occupy a large area. One conventional arrangement includes a bulk
capacitor of microFarads and a multi-layer chip capacitor (MLCC)
having hundreds of nanoFarads along with the voltage regulator on
the PCB. The combination of the bulk capacitor and the MLCC
supplies voltage to the die while the voltage regulator responds to
the current transient.
[0007] Attempts have been made to place voltage regulators on the
dies. However, voltage regulators include passive components such
as inductors and capacitors that are also embedded in the dies.
Passive devices consume die area, which increases manufacturing
cost. For example, a die manufactured using 45 nm technology has a
capacitance density of 10 femtoFarads/.mu.m.sup.2. At this density
a suitable amount of capacitance may consume over 2.5 mm.sup.2.
Providing inductance to the voltage regulator conventionally uses
an on-die inductor or a discrete inductor mounted on the packaging
substrate. In addition to consuming large areas on a die,
conventional on-die inductors have a low quality factor.
[0008] A quality factor for passive components embedded in a die is
low because the passive components are manufactured thin to fit in
the die. As the amount of conducting material shrinks, conductive
or magnetic losses increase and degrade the quality factor. The
quality factor is defined by the energy stored in a passive
component versus energy dissipated in the passive component, for a
passive component embedded in a die is low.
[0009] Thus, there is a need for a voltage regulator that is in
close proximity to the die without consuming large amounts of die
area.
BRIEF SUMMARY
[0010] According to one aspect of the disclosure, a voltage
regulator has a passive portion at least partially embedded in a
packaging substrate. The voltage regulator also has an an active
portion fabricated in a die coupled to the passive portion.
[0011] According to another aspect of the disclosure, a method of
supplying voltage to a die mounted on a packaging substrate
includes mounting an active portion of a voltage regulator on the
packaging substrate. The method also includes coupling the active
portion of the voltage regulator to at least one passive component
at least partially embedded in the packaging substrate. The method
further includes coupling the die to the at least one passive
component.
[0012] According to yet another aspect of the disclosure, a method
of supplying power to a die includes providing a supply voltage to
an active portion of a voltage regulator mounted on a packaging
substrate mounted on a printed circuit board. The method also
includes passing the supply voltage from the active portion of the
voltage regulator to at least one inductor at least partially
embedded in the packaging substrate. The method further includes
passing the supply voltage from the at least one inductor to at
least one capacitor at least partially embedded in the packaging
substrate. The method also includes passing the supply voltage from
the at least one capacitor to the die.
[0013] According to a further aspect of the disclosure, a
semiconductor packaging system includes a packaging substrate into
which at least one means for storing energy is at least partially
embedded. The semiconductor packaging system also includes means
for regulating voltage mounted on the packaging substrate. The
regulating voltage means cooperating with the energy storing
means.
[0014] The foregoing has outlined rather broadly the features and
technical advantages of the present disclosure in order that the
detailed description that follows may be better understood.
Additional features and advantages will be described hereinafter
which form the subject of the claims of the disclosure. It should
be appreciated by those skilled in the art that the conception and
specific embodiments disclosed may be readily utilized as a basis
for modifying or designing other structures for carrying out the
same purposes of the present disclosure. It should also be realized
by those skilled in the art that such equivalent constructions do
not depart from the technology of the disclosure as set forth in
the appended claims. The novel features which are believed to be
characteristic of the disclosure, both as to its organization and
method of operation, together with further objects and advantages
will be better understood from the following description when
considered in connection with the accompanying figures. It is to be
expressly understood, however, that each of the figures is provided
for the purpose of illustration and description only and is not
intended as a definition of the limits of the present
disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] For a more complete understanding of the present disclosure,
reference is now made to the following description taken in
conjunction with the accompanying drawings.
[0016] FIG. 1 is a block diagram showing an exemplary wireless
communication system in which an embodiment of the disclosure may
be advantageously employed.
[0017] FIG. 2 is a block diagram illustrating a design workstation
used for circuit, layout, and logic design of the disclosed
semiconductor IC package.
[0018] FIG. 3 is a cross-sectional view illustrating a conventional
voltage regulator on a printed circuit board.
[0019] FIG. 4 is a block diagram illustrating an exemplary voltage
regulator on a die according to a first embodiment.
[0020] FIG. 5 is a cross-sectional view illustrating an exemplary
voltage regulator on a die with an embedded parasitic inductance
according to a second embodiment.
[0021] FIG. 6 is a cross-sectional view illustrating an exemplary
voltage regulator on a packaging substrate according to a third
embodiment.
[0022] FIG. 7A is a cross-sectional view illustrating an exemplary
voltage regulator on a packaging substrate with a parasitic
inductance according to a fourth embodiment.
[0023] FIG. 7B is a cross-sectional view illustrating an exemplary
voltage regulator with a wirebond inductance according to a fifth
embodiment.
[0024] FIGS. 8A-C are block diagram illustrating paths through a
packaging substrate and printed circuit board that may provide
inductance.
DETAILED DESCRIPTION
[0025] FIG. 1 is a block diagram showing an exemplary wireless
communication system 100 in which an embodiment of the disclosure
may be advantageously employed. For purposes of illustration, FIG.
1 shows three remote units 120, 130, and 150 and two base stations
140. It will be recognized that wireless communication systems may
have many more remote units and base stations. Remote units 120,
130, and 150 include IC devices 125A, 125B and 125C, as disclosed
below. It will be recognized that any device containing an IC may
also include semiconductor components having the disclosed features
and/or components manufactured by the processes disclosed here,
including the base stations, switching devices, and network
equipment. FIG. 1 shows forward link signals 180 from the base
station 140 to the remote units 120, 130, and 150 and reverse link
signals 190 from the remote units 120, 130, and 150 to base
stations 140.
[0026] In FIG. 1, the remote unit 120 is shown as a mobile
telephone, the remote unit 130 is shown as a portable computer, and
the remote unit 150 is shown as a fixed location remote unit in a
wireless local loop system. For example, the remote units may be a
device such as a music player, a video player, an entertainment
unit, a navigation device, a communications device, a personal
digital assistant (PDA), a fixed location data unit, and a
computer. Although FIG. 1 illustrates remote units according to the
teachings of the disclosure, the disclosure is not limited to these
exemplary illustrated units. The disclosure may be suitably
employed in any device which includes semiconductor components, as
described below.
[0027] FIG. 2 is a block diagram illustrating a design workstation
for circuit, layout, and design of a semiconductor part as
disclosed below. A design workstation 200 includes a hard disk 201
containing operating system software, support files, and design
software such as Cadence or OrCAD. The design workstation 200 also
includes a display to facilitate design of a semiconductor part 210
that may include a circuit and semiconductor dies. A storage medium
204 is provided for tangibly storing the semiconductor part 210.
The semiconductor part 210 may be stored on the storage medium 204
in a file format such as GDSII or GERBER. The storage medium 204
may be a CD-ROM, DVD, hard disk, flash memory, or other appropriate
device. Furthermore, the design workstation 200 includes a drive
apparatus 203 for accepting input from or writing output to the
storage medium 204.
[0028] Data recorded on the storage medium 204 may specify logic
circuit configurations, pattern data for photolithography masks, or
mask pattern data for serial write tools such as electron beam
lithography. Providing data on the storage medium 204 facilitates
the design of the semiconductor part 210 by decreasing the number
of processes for designing circuits and semiconductor dies.
[0029] FIG. 3 is a cross-sectional view illustrating a conventional
voltage regulator on a printed circuit board. An IC product 300
includes a printed circuit board (PCB) 310 that supports packaging
substrates and provides communication between packaging substrates
on the PCB 310. A packaging substrate 320 is coupled to the PCB 310
through a packaging connection 322 such as bumps or pillars and
includes through vias 324 to enable communications between the PCB
310 and a die 330. The die 330 is coupled to the packaging
substrate 320 through an interconnect structure 332 such as bumps
or pillars.
[0030] A voltage regulator 340 is coupled to the PCB 310 through a
packaging connection 342. The voltage regulator 340 conventionally
couples to discrete passive components such as inductors and
capacitors mounted on the PCB 310. Low inductance passes (not
shown) provide power from the voltage regulator 340 to the die 330.
The low inductance passes are restricted in location on the PCB
310, which also restricts location of the voltage regulator 340.
Thus, the distance between the voltage regulator 340 and the die
330 has a fixed minimum based on the PCB 310.
[0031] For the reasons discussed above including large voltage drop
between the voltage regulator and the die, slow response times due
to distance from the die to the voltage regulator, increased PCB
size, the use of large decoupling capacitors, and the use of
additional pins on the die to communicate with the voltage
regulator, locating a voltage regulator on the PCB separate from
the packaging substrate may not provide sufficient voltages to the
die for proper operation. If the supply voltage drops below an
acceptable level, the circuits on the die may output incorrect
results or stop working completely.
[0032] According to one embodiment, a voltage regulator may be
integrated into the die. An integrated voltage regulator in the die
does not use additional pins for communicating with the die.
Instead, communication occurs through interconnects in the die. The
integrated voltage regulator is also closer to the die resulting in
quicker response times to current transients and smaller decoupling
capacitors to filter the output of the voltage regulator.
Furthermore, passive components may be embedded in the packaging
substrate to reduce area on the die occupied by the voltage
regulator.
[0033] Passive components may be embedded in a packaging substrate
or a PCB. Embedding the passive components maintains a short path
having low inductance from the voltage regulator to the die.
Further, the voltage regulator control loop bandwidth is increased
by the higher switching frequency and shortened feedback path
between the voltage regulator and the die.
[0034] Larger inductance values are achieved by embedding passive
components in comparison to conventional parasitic air-core
inductors in packaging substrate routing or PCB routing. Embedding
passive components also reduces die size by reducing or eliminating
discrete passive components of the voltage regulator, which may
otherwise be located side-by-side with the die.
[0035] FIG. 4 is a cross-sectional view illustrating an exemplary
voltage regulator on a die according to a first embodiment. An IC
product 400 includes a packaging substrate 420 coupled to a PCB 410
through a packaging connection 422 such as bumps or pillars. The
packaging substrate 420 includes embedded passive components that
may store energy in magnetic or electric form. For example, an
embedded inductor 450 and an embedded capacitor 460 are at least
partially embedded in the packaging substrate 420. The embedded
inductor 450 and/or the embedded capacitor 460 may use embedded die
substrate (EDS) technology. In one embodiment, the embedded
capacitor 460 may have capacitance values in the hundreds of
nanoFarads and provide decoupling capacitance to a die 430. The die
430 is coupled to the packaging substrate 420 through an
interconnect structure 432 such as bumps or pillars.
[0036] Manufacturing the embedded inductor 450 and the embedded
capacitor 460 in the packaging substrate 420 may use a lamination
process according to one embodiment. For example, the packaging
substrate 420 may start as a core with two internal layers
separated by a thick dielectric layer. Holes are placed in the
substrate using a laser drilling process and tape placed on a
backside of the core. The holes are filled to form the embedded
inductor 450 and the embedded capacitor 460, and a top side of the
core is laminated. The embedded inductor 450 may be, for example,
non air-core inductors to obtain higher inductance values than
air-core inductors. Next, tape is peeled off the back side of the
core, and the back side of the core is laminated. The inductance of
the embedded inductor 450 and the capacitance of the embedded
capacitor 460 are selected, in part, from parameters including a
supply voltage of the die 430 and an operating frequency of the die
430. Passive components located in the packaging substrate 420 may
use thicker copper than passive components located in a die and
thus have smaller losses and a higher quality (Q) factor.
[0037] An active portion of a voltage regulator 440 is fabricated
on the die 430 and includes, for example, a driver stage, a
feedback stage, and/or a digital controller. The active portion of
the voltage regulator 440 communicates with the embedded inductor
450 through an electrical path 426. An electrical path 427 couples
the embedded inductor 450 to the embedded capacitor 460. An
electrical path 428 couples the embedded capacitor 460 to the die
430. An electrical path 424 enables communication from the die 430
to the PCB 410. The electrical path 424 may be used, for example,
to provide voltage to the active portion of the voltage regulator
440. That is, regulated voltage provided to the die 430 passes
through the electrical path 424 to the active portion of the
voltage regulator 440, then to the embedded inductor 450, and the
embedded capacitor 460.
[0038] In one embodiment, the active portion of the voltage
regulator 440 is integrated in the die 430. Thus, the active
portion of the voltage regulator 440 responds quickly to current
transients that occur in the die 430. According to one embodiment,
the active portion of the voltage regulator 440 has a response
frequency of approximately 200 MHz. Additionally, embedded passive
components such as the embedded inductor 450 and the embedded
capacitor 460 in the packaging substrate 420 reduce area on the die
430 that would otherwise be occupied by passive components. The
voltage regulator 440 with embedded passive components as described
above may, according to one embodiment, provide currents of several
amps to the die 430.
[0039] In an alternative configuration, some of the embedded
passive components may be replaced with vias in the packaging
substrates. FIG. 5 is a cross-sectional view illustrating an
exemplary voltage regulator on a die with an embedded parasitic
inductance according to a second embodiment.
[0040] The packaging substrate 420 includes vias 526 having a
parasitic inductance used by the active portion of the voltage
regulator 440 as inductors for supplying voltage to the die 430.
The vias 526 may be through vias, which extend the entire height of
the packaging substrate 420. The through vias 526 may be coupled
through the packaging connection 422 to through vias 516 in the PCB
410 if a larger inductance is desired than obtained with the
through vias 526 alone. The use of parasitic inductance in through
vias within the packaging substrate as a passive component
simplifies semiconductor manufacturing by reducing a number of
processes to embed inductors in the packaging substrate.
[0041] According to a third embodiment, an active portion of a
voltage regulator may be separated from the die and mounted on the
packaging substrate. FIG. 6 is a cross-sectional view illustrating
an exemplary voltage regulator on a packaging substrate according
to a third embodiment. An IC product 600 includes a packaging
substrate 620 coupled to a PCB 610 through a packaging connection
622 such as bumps or pillars. A die 630 is coupled to the packaging
substrate 620 through an interconnect structure 632 such as bumps
or pillars. Additionally, an active portion of a voltage regulator
640 is coupled to the packaging substrate 620 through an
interconnect structure 642 such as bumps or pillars. Inside the
packaging substrate 620 is an embedded inductor 650 and an embedded
capacitor 660.
[0042] The embedded capacitor 660 is coupled to the die 630 through
an electrical path 628 and to the embedded inductor 650 through an
electrical path 627. The embedded inductor 650 is coupled to the
active portion of the voltage regulator 640 by an electrical path
626. Voltage is provided to the active portion of the voltage
regulator 640 by an electrical path 624 from the PCB 610 through
the packaging connection 622, the electrical path 624, and the
interconnect structure 642.
[0043] The voltage regulator of FIG. 6 is an off-die voltage
regulator coupled to the same packaging substrate as the die to
which the voltage regulator supplies voltage. Locating the active
portion of the voltage regulator on the packaging substrate but
separate from the die allows different processes to be used for
manufacturing the active portion of the voltage regulator and the
die. For example, the die may be fabricated with 32 nm or 45 nm
processes while the active portion of the voltage regulator may be
fabricated with 0.18 .mu.m processes. Additionally, the active
portion of the voltage regulator may be manufactured at a different
fabrication site than the die.
[0044] Turning now to a fourth embodiment, some of the embedded
passive components may be replaced with vias in the packaging
substrates. FIG. 7A is a cross-sectional view illustrating an
exemplary voltage regulator on a packaging substrate with a
parasitic inductance according to a fourth embodiment. An IC
product 700 includes vias 726 in the packaging substrate 620 having
a parasitic inductance that act as a filter for voltage provided
from the active portion of the voltage regulator 640. Additional
vias 716 in the PCB 610 may couple to the vias 726 through the
packaging connection 622, if additional inductance is desired. The
vias 716 are coupled through a conducting layer 730 on the PCB 610.
The vias 716 or the vias 726 may be through vias, which extend the
entire height of the PCB 610 or the packaging substrate 620,
respectively.
[0045] Voltage is provided to the active portion of the voltage
regulator 640, for example, through the electrical path 624.
Regulated voltage is then output to the vias 726 and the vias 716.
An electrical path 727 couples one of the vias 726 to the embedded
capacitor 660, which is coupled to the die 630 through the
electrical path 628.
[0046] According to a fifth embodiment, inductance is provided by
wirebonds. FIG. 7B is a cross-sectional view illustrating an
exemplary voltage regulator with a wirebond inductance. A wirebond
750 couples the active portion of the voltage regulator 640 to one
of the vias 716. The wirebond 750, the vias 716 and the conducting
layer 730 provide inductance to the active portion of the voltage
regulator 640.
[0047] Embedded passives in which through vias provide inductance
for a voltage regulator will now be described in further detail.
FIGS. 8A-C are block diagrams illustrating paths through a
packaging substrate and PCB that may provide inductance. FIG. 8A is
a block diagram illustrating a path 800 through a packaging
substrate and PCB according to one embodiment. A top conductive
layer 802 and a bottom conductive layer 810 of a packaging
substrate are shown. Inner layers 804, 806 of the packaging
substrate are also shown. A through via 805, couples the top
conductive layer 802 and the bottom conductive layer 810. A
packaging connection 812 may be a bump of a ball grid array and
couples the bottom conductive layer 810 to a top conductive layer
820 of a PCB. A through via 822 couples the top conductive layer
820 to a bottom conductive layer 830. The bottom conductive layer
830 may be an interconnect that couples to another through via in
the PCB. The amount of inductance in the path 800 is proportional
to a length of the path 800.
[0048] FIG. 8B is a block diagram illustrating a path 840 having a
longer length than the path 800. A bottom conductive layer 842
couples the through via 822 to another through via in the PCB. The
bottom conductive layer 842 includes extra length, for example in a
coil, which increases the inductance of the path 840.
[0049] FIG. 8C is a block diagram illustrating a path 850 having a
longer length than the path 830. An inductor coil 852 mounted on a
back side of the PCB couples the through via 822 to another through
via in the PCB. In this embodiment, a coiled wire 854 wraps around
a block 852 to extend the length of the path 850.
[0050] A voltage regulator with passives embedded in packaging
maintains a short and low inductive path from the voltage regulator
to the die. Additionally, increased voltage regulator control loop
bandwidth increases operating frequency and shortens a feedback
path to the voltage regulator. Passive components embedded in the
packaging substrate allows increased inductance and capacitance
values. Further, the embedded passive components reduce packaging
substrate top side area consumed by passive components.
[0051] Although the terminology "through silicon via" includes the
word silicon, it is noted that through silicon vias are not
necessarily constructed in silicon. Rather, the material can be any
device substrate material.
[0052] Although the present disclosure and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the technology of the disclosure as defined by the appended
claims. Moreover, the scope of the present application is not
intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
disclosure, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the present
disclosure. Accordingly, the appended claims are intended to
include within their scope such processes, machines, manufacture,
compositions of matter, means, methods, or steps.
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