U.S. patent application number 10/927014 was filed with the patent office on 2005-03-03 for integrated circuit package having inductance loop formed from same-pin-to-same-bonding-pad structure.
This patent application is currently assigned to GCT Semiconductor, Inc.. Invention is credited to Huh, Hyungki, Koo, Yido, Lee, Jeong-Woo, Lee, Kang Yoon, Lee, Kyeongho, Park, Joonbae.
Application Number | 20050045987 10/927014 |
Document ID | / |
Family ID | 34272660 |
Filed Date | 2005-03-03 |
United States Patent
Application |
20050045987 |
Kind Code |
A1 |
Koo, Yido ; et al. |
March 3, 2005 |
Integrated circuit package having inductance loop formed from
same-pin-to-same-bonding-pad structure
Abstract
An integrated circuit package includes an inductance loop formed
from a connection of bonding wires and one or more input/output
(I/O) package pins. In one embodiment, the inductance loop is
formed from a first wire which connects a bonding pad on the
integrated circuit chip to an I/O pin of the package and a second
wire which connects the same bonding pad to the same pin. By
forming the inductor loop within the limits of the integrated
circuit package, a substantial reduction in space requirements is
realized, which, in turn, promotes miniaturization.
Inventors: |
Koo, Yido; (Seoul, KR)
; Huh, Hyungki; (Seoul, KR) ; Lee, Kang Yoon;
(Seoul, KR) ; Lee, Jeong-Woo; (Seoul, KR) ;
Park, Joonbae; (Seoul, KR) ; Lee, Kyeongho;
(Seoul, KR) |
Correspondence
Address: |
FLESHNER & KIM, LLP
P.O. BOX 221200
CHANTILLY
VA
20153
US
|
Assignee: |
GCT Semiconductor, Inc.
|
Family ID: |
34272660 |
Appl. No.: |
10/927014 |
Filed: |
August 27, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60498353 |
Aug 28, 2003 |
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Current U.S.
Class: |
257/531 ;
257/691; 257/692; 257/723 |
Current CPC
Class: |
H01L 2924/01023
20130101; H01L 2224/49111 20130101; H01L 2924/014 20130101; H01L
2924/00014 20130101; H01L 2924/00014 20130101; H01L 2924/14
20130101; H01L 24/48 20130101; H01L 2924/19043 20130101; H01L 24/49
20130101; H01L 2924/01082 20130101; H01L 2924/01005 20130101; H01L
2924/19042 20130101; H01L 2924/30107 20130101; H01L 2224/48091
20130101; H01L 23/645 20130101; H01L 2224/48247 20130101; H01L
2224/49111 20130101; H01L 2924/19041 20130101; H01L 2224/48091
20130101; H01L 2924/01006 20130101; H01L 2924/00014 20130101; H01L
2924/01033 20130101; H01L 2224/05599 20130101; H01L 2924/00014
20130101; H01L 2224/45099 20130101; H01L 2224/48247 20130101; H01L
2924/00 20130101 |
Class at
Publication: |
257/531 ;
257/691; 257/692; 257/723 |
International
Class: |
H01L 023/52; H01L
029/00 |
Claims
We claim:
1. A semiconductor package, comprising: an integrated circuit chip;
and an inductor loop including a first conductor connecting a
bonding pad on the chip to an input/output pin of the package, and
a second conductor connecting the bonding pad on the chip to the
input/output pin of the package.
2. The semiconductor package of claim 1, wherein the first
conductor and the second conductor are bonding wires.
3. The semiconductor package of claim 1, wherein the inductor loop
includes at least a third conductor connecting the bonding pad on
the chip to the input/output pin of the package.
4. A semiconductor package, comprising: an integrated circuit chip;
and an inductor loop including: (a) a first sub-loop which includes
a first conductor connecting a bonding pad on the chip to an
input/output pin of the package and second conductor connecting the
bonding pad on the chip to the input/output pin of the package; and
(b) a second sub-loop which includes one of the first conductor and
the second conductor and a third conductor connecting the bonding
pad on the chip to the input/output pin of the package.
5. The semiconductor package of claim 4, wherein the first
conductor and the second conductor are bonding wires.
6. A semiconductor package, comprising: an integrated circuit chip
including a phase-locked loop; and an inductor loop having a length
corresponding to an output frequency of the phase-locked loop, said
inductor loop including a first conductor connecting a bonding pad
on the chip to an input/output pin of the package, and a second
conductor connecting the bonding pad on the chip to the
input/output pin of the package.
7. The semiconductor package of claim 6, wherein the first
conductor and the second conductor are bonding wires.
8. An oscillator circuit, comprising: an active oscillator having
two output nodes; an inductor loop coupled to the output nodes; and
at least one capacitive circuit coupled to one of the output nodes,
said capacitive circuit including a capacitor, a resistor, and a
first switch, wherein said resistor provides a bias voltage to the
capacitor when the first switch is open and wherein said first
switch couples and decouples the capacitor to the output nodes of
the active oscillator, and wherein the active oscillator and
capacitive circuit are included in a semiconductor package which
includes an integrated circuit chip, said inductor loop including a
first conductor connecting a bonding pad on the chip to an
input/output pin of the package and a second conductor connecting
the bonding pad on the chip to the input/output pin of the
package.
9. The oscillator circuit of claim 8, wherein the first conductor
and the second conductor are bonding wires.
10. The oscillator circuit of claim 8, wherein the inductor loop
includes at least a third conductor connecting the bonding pad on
the chip to the input/output pin of the package.
11. An oscillator circuit, comprising: an active oscillator having
two output nodes; an inductor loop coupled to the output nodes; and
at least one capacitive circuit coupled to one of the output nodes,
said capacitive circuit including a capacitor, a resistor, and a
first switch, wherein said resistor provides a bias voltage to the
capacitor when the first switch is open and wherein said first
switch couples and decouples the capacitor to the output nodes of
the active oscillator, and wherein the active oscillator and
capacitive circuit are included in a semiconductor package which
includes an integrated circuit chip, said inductor loop including:
(a) a first sub-loop which includes a first conductor connecting a
bonding pad on the chip to an input/output pin of the package and
second conductor connecting the bonding pad on the chip to the
input/output pin of the package; and (b) a second sub-loop which
includes one of the first conductor and the second conductor and a
third conductor connecting the bonding pad on the chip to the
input/output pin of the package.
12. The oscillator circuit of claim 11, wherein the first conductor
and the second conductor are bonding wires.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention generally relates to integrated circuits, and
more particularly to an integrated circuit package having an
inductance loop formed from at least one input/output pin of the
package.
[0003] 2. Description of the Related Art
[0004] One perennial goal among circuit designers is to decrease
the size of integrated circuits. This goal is largely driven by
market demand for ever-smaller consumer electronics, communications
devices, and display systems to mention a few. There are, however,
a number of impediments that undermine this goal, one of which will
now be discussed.
[0005] Many integrated circuits are not self-contained devices. To
ensure proper operation, these circuits must therefore be connected
to one or more external components through connections which do not
involve the use of an IC package input/output pin. This is
accomplished, for example, by connecting the integrated circuit
chip 1 to an off-package component 2 using bonding wires 3, as
shown in FIG. 1. The need to establish off-package connections
increases the cost and complexity of the manufacturing process and
therefore is considered highly undesirable. These connections also
expose the integrated circuit to an increased risk of damage from
external influences, which translate into degradation in
reliability and performance.
[0006] One conventional integrated circuit requiring off-package
connections is routinely used in the frequency synthesizer of
mobile communications devices such as cellular phones. Because the
phase noise specifications are so stringent in these devices,
voltage-controlled oscillators in a phase-locked loop used to
generate the frequencies are typically based on some resonant
structure. Ceramic resonators and LC tank circuits are common
examples. While details in the implementation of LC tank
oscillators differ, the general resonant structure includes an
inductor connected in parallel with a fixed capacitor (C) and a
variable capacitor (C.sub.x). In the absence of any losses, energy
passes between the capacitors and the inductor at a frequency
f.sub.out=(1/2.pi.) [L(C+C.sub.x)].sup.-1/2, with the inductance
value L selected to control the operating band of the device.
[0007] In an integrated circuit which includes the aforementioned
frequency synthesizer, the inductor used for band-selection
purposes is located off-package (i.e., is circuit-board mounted).
The use of off-package or board-mounted inductors increases system
costs. Moreover, connection problems may occur between the package
and board which may adversely affect the reliability and
performance of the PLL circuitry.
[0008] Attempts have been made to overcome the drawbacks of these
conventional devices. One approach, disclosed in U.S. Pat. No.
6,323,735, forms an inductor entirely within the integrated circuit
package containing the phase-locked loop circuitry. This is
accomplished using conductive wires which connect bonding pads on
the IC chip to a same bonding pad on the package substrate. The
connection between the pads and wires forms an inductance loop
which controls the operational frequency band of the PLL circuitry.
Multiple bonding pads may be included on the package substrate to
form inductor loops of varying length. The loops are then
selectively activated to effect a change in operational
frequency.
[0009] The approach taken in the '735 patent is undesirable for at
least two reasons. First, in order to form the inductor loop
completely within the IC package, the package substrate must be
formed to include bonding pads separate from the input/output
package pins. The need to form these special pads increases the
cost and complexity of the manufacturing process. Second, in order
to accommodate the bonding pads, the size of the integrated circuit
substrate must be increased and as a result more circuit board
space is consumed. These effects undermine the goal of increasing
integration and miniaturization.
[0010] Another approach, disclosed in the text "Wireless CMOS
Frequency Synthesizer Design," by Craninckx, discloses a
self-contained integrated circuit package containing an inductor
loop. This loop is formed by connecting bonding wires between
bonding pads on the IC chip and respective input/output pins of the
IC package. The input/output pins are then connected by a third
bonding wire. While this approach does not require the formation of
special bonding pads on the package substrate, it is has at least
two drawbacks that make it undesirable. First, like in the '735
patent, a bonding wire is used to connect the input/output pins. As
previously noted, these wires are susceptible to damage during
manufacture and/or use. Second, the input/output pins connected by
the third bonding wire are located on opposite sides of the
package. As a result, the third wire must pass over the IC chip.
This is undesirable because the wire could short certain portions
of the chip circuitry and introduce noise and other interfering
influences which substantially degrade chip performance.
[0011] In view of the foregoing considerations, it is apparent that
a need exists for an integrated circuit package which is more
economical and requires fewer processing steps to manufacture than
conventional IC packages, and which is also less susceptible to
damage and noise which can degrade reliability and performance not
only of the chip circuitry but also the host system of the chip. A
need also exists for an integrated circuit package which is
self-contained at least with respect to connection of an inductor
loop connected to the chip, and which is able through this
connection to achieve at least one of the aforementioned
advantages.
SUMMARY OF THE INVENTION
[0012] An object of the present invention is to provide an
integrated circuit package which is more economical and requires
fewer processing steps to manufacture than conventional IC
packages.
[0013] Another object of the present invention is to provide an
integrated circuit package which is less susceptible to damage and
noise which can degrade reliability and performance not only of the
chip circuitry but also of the host system of the chip.
[0014] Another object of the present invention is to provide an
integrated circuit package which is self-contained at least with
respect to connection of an inductor loop to the IC chip and which
is able through this connection to achieve at least one of the
aforementioned advantages.
[0015] Another object of at least one embodiment of the present
invention is to accomplish one or more of the aforementioned
objects by reducing the number of bonding wires used to form the
inductor loop compared with the number of wires used in
conventional self-contained integrated circuits.
[0016] Another object of the present invention is to provide an
integrated circuit package which does not require special bonding
pads to be formed on the package substrate in order to form an
inductor loop connected to the chip.
[0017] Another object of the present invention is to achieve one or
more of the aforementioned objects by forming the inductor loop
from at least one input/output pin of the package.
[0018] These and other objects and advantages of the present
invention are achieved by providing a semiconductor package
comprising an integrated circuit chip and an inductor loop which is
connected in a self-contained manner within the package. This
self-contained connection is accomplished by forming the loop from
at least two conductors. The first conductor connects a bonding pad
on the chip to an input/output pin of the package. The second
conductor connects the same bonding pad on the chip to the same
input/output pin of the package, thereby forming a loop. At least a
third conductor may be added between the same pin and pad to
increase the effective length of the inductor to thereby achieve a
desired inductance. The conductors are preferably bonding
wires.
[0019] In accordance with another embodiment, the semiconductor
package comprises an integrated circuit chip and an inductor loop
which is connected in a self-contained manner within the package.
This inductor loop is formed from a plurality of sub-loops. The
first sub-loop includes a first conductor which connects a bonding
pad on the chip to an input/output pin of the package and a second
conductor which connects the same bonding pad to the same pin. The
second sub-loop includes one of the first and second conductors and
a third conductor connected between the pin and pad. The conductors
are preferably bonding wires.
[0020] The present invention is also an oscillator circuit which
includes an active oscillator having two output nodes, an inductor
loop coupled to the output nodes, and at least one capacitive
circuit coupled to one of the output nodes. The capacitive circuit
includes a capacitor, a resistor, and a first switch and the
resistor provides a bias voltage to the capacitor when the first
switch is open. The first switch couples and decouples the
capacitor to the output nodes of the active oscillator. Preferably,
the active oscillator and capacitive circuit are included in a
semiconductor package which includes an integrated circuit chip.
When configured in this manner, the inductor loop includes a first
conductor connecting a bonding pad on the chip to an input/output
pin of the package and a second conductor connecting the bonding
pad on the chip to the input/output pin of the package. The first
and second conductors may be bonding wires and the inductor loop
may include at least a third conductor connecting the bonding pad
on the chip to the input/output pin of the package.
[0021] In accordance with another embodiment, the present invention
provides an oscillator circuit as previously described but with a
different inductor loop configuration. This inductor loop includes
has two sub-loops, the first of which includes a first conductor
connecting a bonding pad on the chip to an input/output pin of the
package and second conductor connecting the bonding pad on the chip
to the input/output pin of the package. The second sub-loop
includes one of the first conductor and the second conductor and a
third conductor connecting the bonding pad on the chip to the
input/output pin of the package. The first conductor and the second
conductor are bonding wires.
BRIEF DESCRIPTION OF THE DRAWINGS
[0022] FIG. 1 is a diagram showing a conventional integrated
circuit package which is not self-contained.
[0023] FIG. 2 is a diagram showing a semiconductor package in
accordance with a first embodiment of the present invention.
[0024] FIG. 3 is a diagram showing a semiconductor package in
accordance with a second embodiment of the present invention.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0025] The present invention is, in one respect, a semiconductor
package having an integrated circuit chip and an inductor loop
which is connected in a self-contained manner within the package.
The present invention is also a system which is at least partially
controlled by the inductor loop of the semiconductor device
mentioned above. The system may be a communications system where
the inductor loop is used to set a transmitter and/or RF carrier
frequency or another type of system. The various embodiments of the
invention will now be discussed in seriatim below.
[0026] FIG. 2 shows a semiconductor package in accordance with a
first embodiment of the present invention. This package includes an
integrated circuit chip 10 mounted on or within a package housing
11. The housing includes a substrate 12 for supporting the chip and
a plurality of input/output (I/O) pins 13 formed on the substrate
for electrically connecting the chip to one or more external
circuits (not shown). The substrate may be any type known and the
I/O pins may be connected to the chip using any one of a variety of
conventional attachment techniques, including but not limited to
wire bonds and solder bumps. Examples of packages of this type
include lead frame packages, ball grid array (BGA) packages
including those using tape automated bonding (FAB), pin grid array
packages (PGA), thin small outline packages (TSOP), small outline
J-lead packages (SOJ); small outline packages (SOP), and chip scale
packages (CSP) to name a few.
[0027] The I/O pins may take any one of a variety of forms. For
example, the pins are shown as external package leads disposed
along a periphery of the package substrate. However, if desired the
pins may be formed in other ways including but not limited to
electrically conductive vias which extend through the package
substrate to solder bump connections provided on an opposing side
of the package.
[0028] The semiconductor package also includes an inductor loop 20
self-contained within the package. The inductor loop may be formed
from two conductors. The first conductor 22 connects a first
bonding pad 24 on the chip to a first input/output pin 26 of the
package, and the second conductor 23 connects the same bonding pad
to the same input/output pin. In this embodiment, the pin connects
the two conductors to thereby complete the loop. The first and
second conductors are preferably bonding wires.
[0029] Once the inductor loop is formed, it may be used to control
one or more circuits on the integrated circuit chip. For example,
if the integrated circuit includes a phase-locked loop, the
inductance value of the loop may be used to set an output frequency
or frequency band of this circuit. Alternatively, the length of the
loop may be used to set other operational parameters of the chip.
The inductance value of the loop depends on its overall length.
This length may be set in various ways to achieve the desired
inductance value. For example, the length of the first and second
conductors may be set to have specific lengths based on a loop
length to be achieved. The specific application of the inductor
loop of the present invention may be adapted, for example,
depending upon the parameters being set and the specific function
to be performed by the integrated circuit.
[0030] FIG. 3 shows a semiconductor package in accordance with a
second embodiment of the present invention. This package includes
an integrated circuit chip 100 mounted on or within a package
housing 110. The housing includes a substrate 112 for supporting
the chip and a plurality of input/output (I/O) pins 113 formed on
the substrate for electrically connecting the chip to one or more
external circuits (not shown). The substrate may be made from a
material and the I/O pins may be formed and connected in any of the
ways noted in the discussion of the first embodiment.
[0031] The semiconductor package also includes an inductor loop 120
self-contained within the package. The inductor loop is formed from
two sub-loops. The first sub-loop is formed by connecting a first
conductor 122 between a bonding pad 124 on the chip and a first
input/output pin 126 of the package and a second conductor 133
between the same bonding pad and package pin. The second sub-loop
is formed by one of the first and second conductors and at least a
third conductor 23 connected between the same pad and pin. The
conductors are preferably bonding wires. The inductor loop
therefore has an effective length (and thus an inductance value)
based on the sum of the two sub-loops. Those skilled in the art can
appreciate that additional conductors may be added between the pad
and pin to increase the number of sub-loops comprising the
inductor.
[0032] A semiconductor package in accordance with any of the
aforementioned embodiments may be used in any one of a variety of
applications. One exemplary application is in a communication
system where the inductor loop is used to set one or more
parameters such as but not limited to an operating frequency. One
illustrative embodiment of a voltage-controlled oscillator which
may be included in such a communication system will now be
described.
[0033] Other modifications and variations to the invention will be
apparent to those skilled in the art from the foregoing disclosure.
Thus, while only certain embodiments of the invention have been
specifically described herein, it will be apparent that numerous
modifications may be made thereto without departing from the spirit
and scope of the invention.
* * * * *