U.S. patent application number 14/580147 was filed with the patent office on 2016-06-02 for package for high-power semiconductor devices.
The applicant listed for this patent is TriQuint Semiconductor, Inc.. Invention is credited to Deep C. Dumka, Tarak A. Railkar.
Application Number | 20160155681 14/580147 |
Document ID | / |
Family ID | 51263970 |
Filed Date | 2016-06-02 |
United States Patent
Application |
20160155681 |
Kind Code |
A9 |
Railkar; Tarak A. ; et
al. |
June 2, 2016 |
PACKAGE FOR HIGH-POWER SEMICONDUCTOR DEVICES
Abstract
Methods and apparatuses for forming a package for high-power
semiconductor devices are disclosed herein. A package may include a
plurality of distinct thermal spreader layers disposed between a
die and a metal carrier. Other embodiments are described and
claimed.
Inventors: |
Railkar; Tarak A.; (Plano,
TX) ; Dumka; Deep C.; (Richardson, TX) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TriQuint Semiconductor, Inc. |
Hillsboro |
OR |
US |
|
|
Prior
Publication: |
|
Document Identifier |
Publication Date |
|
US 20150104906 A1 |
April 16, 2015 |
|
|
Family ID: |
51263970 |
Appl. No.: |
14/580147 |
Filed: |
December 22, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
13769729 |
Feb 18, 2013 |
8946894 |
|
|
14580147 |
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Current U.S.
Class: |
438/113 |
Current CPC
Class: |
H01L 2924/01322
20130101; H01L 23/34 20130101; H01L 2924/0002 20130101; H01L
2924/01322 20130101; H01L 2924/12042 20130101; H01L 23/373
20130101; H01L 23/3735 20130101; H01L 2924/0002 20130101; H01L
23/3732 20130101; H01L 2924/00 20130101; H01L 24/83 20130101; H01L
2924/00 20130101; H01L 2924/00 20130101; H01L 2924/12042 20130101;
H01L 23/3731 20130101; H01L 21/4882 20130101; H01L 21/78 20130101;
H01L 23/3736 20130101 |
International
Class: |
H01L 23/34 20060101
H01L023/34; H01L 23/00 20060101 H01L023/00; H01L 21/78 20060101
H01L021/78 |
Claims
1. A method comprising: providing a first thermal spreader layer on
a semiconductor material; providing a second thermal spreader layer
on a metal carrier; providing an adhesive on the first thermal
spreader layer or the second thermal spreader layer; coupling the
first thermal spreader layer with the second thermal spreader layer
after said providing of the adhesive.
2. The method of claim 1, wherein the semiconductor material
comprises gallium nitride.
3. The method of claim 1, wherein said providing of the first
thermal spreader layer comprises: forming the first thermal
spreader layer on a wafer of the semiconductor material.
4. The method of claim 3, further comprising: singulating dies from
the wafer after said coupling of the first thermal spreader layer
with the second thermal spreader layer.
5. The method of claim 3, further comprising: singulating dies from
the wafer prior to said coupling of the first thermal spreader
layer with the second thermal spreader layer.
6. The method of claim 3, wherein said providing of the adhesive
further comprises: printing a pattern of the adhesive on the second
thermal spreader layer.
7. The method of claim 1, wherein said providing of the first
thermal spreader layer comprises: forming the second thermal
spreader layer on individual dies of the semiconductor
material.
8. The method of claim 7, further comprising: placing the
individual dies and formed second thermal spreader layer on the
first thermal spreader layer formed on the metal carrier.
9. The method of claim 1, wherein the first and second thermal
spreader layers comprise silicon carbide, diamond, or aluminum
nitride.
10. The method of claim 1, wherein the first and second thermal
spreader layers comprise diamond and are formed by chemical vapor
deposition.
11. The method of claim 1, wherein the adhesive is a sintered
silver or sintered copper.
12. The method of claim 1, wherein said coupling of the first
thermal layer with the second thermal layer comprises: placing the
first and second thermal layers adjacent to one another and curing
the adhesive.
13. The method of claim 1, wherein the metal carrier comprises
copper or aluminum.
14. The method of claim 1, wherein said providing of the first
spreader layer comprises forming the first spreader layer to a
thickness between 25 and 500 microns; and said forming of the
second spreader layer comprises forming the second spreader layer
to a thickness between 25 and 500 microns.
15-22. (canceled)
Description
TECHNICAL FIELD
[0001] Embodiments of the present invention relate generally to
microelectronic devices including packages for high-power
semiconductor devices.
BACKGROUND
[0002] In the current state of technology, there has been an
increased demand for devices with high power density. The
requirements for devices such as microwave- and millimeter-wave
devices, for example, are becoming increasingly stringent. To
accommodate such demands, gallium nitride technology has been used
with favorable results. Problematic, however, is the heat output
with the high power densities associated with gallium nitride.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] Embodiments of the present invention will be readily
understood by the following detailed description in conjunction
with the accompanying drawings. To facilitate this description,
like reference numerals designate like structural elements.
Embodiments of the invention are illustrated by way of example and
not by way of limitation in the figures of the accompanying
drawings.
[0004] FIG. 1 illustrates a package in accordance with various
embodiments of the present invention.
[0005] FIG. 2 is a flowchart depicting operations of manufacturing
a package in accordance with various embodiments of the present
invention.
[0006] FIGS. 3(a), 3(b), 3(c), 3(d), and 3(e) illustrate a
schematic of manufacturing operations of a package in accordance
with various embodiments of the present invention.
[0007] FIG. 4 is a flowchart depicting operations of manufacturing
a package in accordance with various embodiments of the present
invention.
[0008] FIGS. 5(a), 5(b), 5(c), 5(d), 5(e), and 5(f) illustrate a
schematic of manufacturing operations of a package in accordance
with various embodiments of the present invention.
[0009] FIG. 6 is a block diagram of an exemplary radio frequency
system in accordance with various embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0010] In the following detailed description, reference is made to
the accompanying drawings which form a part hereof wherein like
numerals designate like parts throughout, and in which is shown by
way of illustration embodiments in which the invention may be
practiced. It is to be understood that other embodiments may be
utilized and structural or logical changes may be made without
departing from the scope of the present invention. Therefore, the
following detailed description is not to be taken in a limiting
sense, and the scope of embodiments in accordance with the present
invention is defined by the appended claims and their
equivalents.
[0011] Various operations may be described as multiple discrete
operations in turn, in a manner that may be helpful in
understanding embodiments of the present invention; however, the
order of description should not be construed to imply that these
operations are order dependent. Moreover, some embodiments may
include more or fewer operations than may be described.
[0012] The description may use the phrases "in an embodiment," "in
embodiments," or "in various embodiments," which may each refer to
one or more of the same or different embodiments. Furthermore, the
terms "comprising," "including," "having," and the like, as used
with respect to embodiments of the present invention, are
synonymous.
[0013] For the purposes of the present invention, the phrase "A or
B" means "(A), (B), or (A and B)."
[0014] Various embodiments of the present invention are directed to
methods and apparatuses for forming a package for high-power
semiconductor devices. In particular, in accordance with some
embodiments, a package is taught that includes a plurality of
distinct thermal spreader layers disposed between a die and a metal
carrier. Relative to various methods known in the related art,
these embodiments may decrease thermal resistance between dies and
a heat sink. These embodiments may additionally or alternatively
reduce the presence or severity of localized hot spots that may be
associated with areas of the die that have relatively higher power
densities.
[0015] FIG. 1 illustrates a package 100 in accordance with some
embodiments. The package 100 may include a die 104 coupled with a
thermal spreader layer 108. The thermal spreader layer 108 may be
coupled with a thermal spreader layer 112 by an adhesive 116. The
thermal spreader layer 112 may be further coupled with a metal
carrier 120.
[0016] The die 104 may be made of a semiconductor material such as
gallium nitride (GaN). GaN has a high bandgap relative to other
semiconductor materials and, therefore, may operate at relatively
higher voltages and provide relatively higher power densities.
Devices utilizing GaN dies, e.g., GaN high electron mobility
transistors (HEMT) devices, may be used in power management, power
amplification, or other high-power applications. Effective
management of thermal energy sourced from these GaN dies in these
high-power applications may provide a corresponding increase in
performance or longevity of the devices. While embodiments describe
the die 104 as a GaN die, the dies of other embodiments may include
other semiconductor materials such as, but not limited to, gallium
arsenide (GaAs), indium phosphide (InP), or silicon.
[0017] As will be readily understood in the art, the schematic of
FIG. 1 is not shown to scale. In some embodiments, the thicknesses
of the components of the package 100 may be as follows. The die 104
may be approximately 1-5 microns thick; the thermal spreader layer
108 may be approximately 25-500 microns thick; the thermal spreader
layer 112 may be approximately 25-500 microns thick; and the metal
carrier may be approximately 100-2000 microns thick.
[0018] The thermal spreader layers may be composed of materials
having high thermal conductivity to facilitate rapid distribution
of thermal energy sourced from the dies 104 during operation.
Materials having suitably high thermal conductivity include diamond
(thermal conductivity of about 700-2000 Watts per meter Kelvin
(W/mK)), aluminum nitride (AIN) (thermal conductivity of up to
about 300 W/mK), polycrystalline silicon carbide (poly-SiC)
(thermal conductivity of greater than 300 W/mK, carbon nanofibers
(thermal conductivity of 800-2000 or more W/mK), etc.
[0019] The adhesive 116 may be a thermally conductive adhesive such
as, but not limited to, eutectic alloys like gold-tin,
gold-germanium, gold-silicon, etc., or epoxies like sintered
silver, sintered copper, etc. The thermal spreader layers and the
adhesive 116 may provide a channel with a low thermal resistance so
that thermal energy may be rapidly transferred from a heat source,
for example, the die 104, to a heat sink, for example, the metal
carrier 120.
[0020] The metal carrier 120 may be a thermally conductive material
that has sufficient bulk and thermal properties to store and
gradually dissipate absorbed thermal energy. In various
embodiments, the metal carrier 120 may include a metal or metal
alloys such as, but not limited to, copper, aluminum, copper-moly,
copper-tungsten, aluminum-silicon carbide, etc.
[0021] The use of the double layer thermal spreaders, as shown,
provides a number of manufacturing efficiencies, as will be
discussed below, as well as various operating efficiencies. For
example, the close proximity of the thermal spreaders to a heat
sink, for example, metal carrier 120, may assist with efficient
removal of unwanted heat away from the semiconductor device channel
of the die 104. The structure of the package 100 may work to reduce
total thermal resistance in the channel from the die 104 to the
metal carrier 120, as well as reduce the risk of hot-spots on the
die 104.
[0022] While embodiments describe the use of two thermal spreader
layers, other embodiments may include additional thermal spreader
layers. Adhesive layers may be disposed between the different
thermal spreader layers.
[0023] While not specifically shown, the package 100 may be further
packaged for wire-bonding and routing or assembled directly on a
printed circuit board, e.g., a motherboard, a daughterboard, an
application board, etc.
[0024] FIG. 2 is a flowchart depicting an operation 200 to
manufacture a package, for example, package 100, in accordance with
some embodiments. FIG. 3 is a schematic that corresponds to the
operation 200 in accordance with some embodiments. At 204 and FIG.
3(a), the operation 200 may include providing a thermal spreader
layer 308 on a semiconductor material 304. The semiconductor
material 304 may be, for example, GaN and the thermal spreader
layer 308 may be, for example, diamond.
[0025] The providing at 204 may include forming the thermal
spreader layer 308 on the semiconductor material 304 or vice versa.
Forming a layer on another layer may include any type of formation
process including, but not limited to, growing, depositing,
coupling, etc. In some embodiments, the forming may include a
chemical vapor deposition (CVD) process. A CVD process may be
especially useful in forming a diamond thermal spreader layer. In
embodiments in which a thermal spreader layer includes diamond
formed from a CVD process, it may also be referred to as a CVD
diamond thermal spreader layer.
[0026] The operation 200 may further include, at 208 and FIG. 3(b),
providing a thermal spreader layer 312 on a metal carrier 320. The
providing at 208 may be similar to, or different from, the
providing at 204. For example, the providing at 208 may include
forming the thermal spreader layer 312 on the metal carrier 320 or
vice versa.
[0027] In some embodiments, the formation of the thermal spreader
may depend on characteristics of the underlying substrate. For
example, formation of the thermal spreader layer 308 on the
semiconductor material 304 may vary from the formation of the
thermal spreader layer 312 on the metal carrier 320 due to varying
characteristics of the semiconductor material 304 and the metal
carrier 320. In this manner, the two formation processes may be
independently improved.
[0028] The operation 200 may further include, at 212 and FIG. 3(c),
providing an adhesive layer 316 on the thermal spreader layer 308
or the thermal spreader layer 312. In FIG. 3(c), the adhesive layer
316 is shown on the thermal spreader layer 312; however, in other
embodiments, it may be provided in alternative or additional
places, such as, for example, on the thermal spreader layer
308.
[0029] The operation 200 may further include, at 216 and FIG. 3(d),
coupling the thermal spreader layer 308 (and the semiconductor
material on which it is disposed) with the thermal spreader layer
312 (and the metal carrier on which it is disposed). The coupling
of 216 may include placing the thermal spreader layer 308 against
the adhesive layer 316 and the thermal spreader layer 312 and
curing the adhesive layer 316. The curing of the adhesive layer 316
may include application of appropriate amounts of heat and/or
pressure.
[0030] The operation 200 may further include, at 220 and FIG. 3(e),
singulating dies. The singulation of the dies at 220 may be
performed by using mechanical dicing (for example, saw, scribe and
break, etc.), laser sawing, plasma dicing, plasma and mechanical
hybrid dicing, etc.
[0031] FIG. 4 is a flowchart depicting an operation 400 to
manufacture a package, for example, package 100, in accordance with
some embodiments. FIG. 5 is a schematic that corresponds to the
operation 400 in accordance with some embodiments. The operation
400 may be similar to operation 200 except as otherwise noted.
[0032] At 404 and FIG. 5(a), the operation 400 may include
providing a thermal spreader layer 508 on a semiconductor material
504, such as a GaN wafer.
[0033] The operation 400 may further include, at 408 and FIG. 5(b),
singulating dies 502(a) and 502(b). Die 502(a) may include a
semiconductor portion 504(a) and a thermal spreader portion 508(a).
Similarly, die 502(b) may include a semiconductor portion 504(b)
and a thermal spreader portion 508(b).
[0034] The operation 400 may further include, at 412 and FIG. 5(c),
providing thermal spreader layer 512 on metal carrier 520.
[0035] The operation 400 may further include, at 416 and FIG. 5(d),
providing an adhesive layer 516 on the thermal spreader layer 512.
In some embodiments, the adhesive layer 516 may be provided on the
thermal spreader layer 512 as a pattern including adhesive portions
516(a) and 516(b). In some embodiments, the thermal spreader layer
512 may be patterned by use of a screen or a mask.
[0036] The operation 400 may further include, at 420 and FIG. 5(e),
coupling the dies 502 with the thermal spreader layer 512 (and the
metal carrier on which it is disposed). This may include a
pick-and-place process to place the dies 502 on the appropriate
adhesive portions. Subsequently, the adhesive portions may be cured
to securely couple the dies 502 with the thermal spreader layer
512.
[0037] The operation 400 may further include, at 424 and FIG. 5(f),
separating the singulated dies. The separation of the singulated
dies at 424 may be performed by processes similar to singulation
processes used to singulate the dies at 408. However, the
separation operation may be less precise in nature allowing for use
of cheaper and faster separating processes.
[0038] The die-based processing of operation 400 may be associated
with higher yields than the wafer-based processing of operation
200, though it may also be associated with an extra separation
process. The higher yields of operation 400 may be provided due to
the fact that only the dies that meet certain operating criteria,
rather than the wafer as a whole, may be further processed.
[0039] The packages described herein may be particularly suitable
for GaN HEMTs that are incorporated into radio frequency systems
for power management or power amplification at various frequencies,
for example, microwave and/or millimeter wave frequencies. FIG. 6
is a block diagram of a RF system 600 in accordance with various
embodiments. The RF system 600 may be a wireless communication
device that has an RF front-end 604 that includes various
components to facilitate transmission or reception of RF signals.
The components could include, but are not limited to, an antenna
switch module, a transmitter, a receiver, an amplifier, a
converter, a filter, etc.
[0040] In addition to the RF front-end 604, the RF system 600 may
have an antenna 616, a transceiver 620, a processor 624, and a
memory 628 coupled with each other at least as shown. The RF system
600 may further include a power supply 632 coupled to one or more
of the other components to provide appropriate power supplies. In
various embodiments, GaN HEMTs (or other devices) packaged in
accordance the present teachings may be employed in a power
management application of the power supply 632, an amplification
application of the RF front-end 604, or other application.
[0041] The processor 624 may execute a basic operating system
program, stored in the memory 628, in order to control the overall
operation of the wireless communication device 600. For example,
the processor 624 may control the reception of signals and the
transmission of signals by the transceiver 620. The processor 624
may be capable of executing other processes and programs resident
in the memory 628 and may move data into or out of the memory 628
as desired by an executing process.
[0042] The transceiver 620 may receive outgoing data (e.g., voice
data, web data, e-mail data, signaling data, etc.) from the
processor 624, may generate RF signal(s) to represent the outgoing
data, and provide the RF signal(s) to the RF front-end 604.
Conversely, the transceiver 620 may receive RF signals from the RF
front-end 604 that represent incoming data. The transceiver 620 may
process the RF signals and send incoming signals to the processor
624 for further processing.
[0043] The RF front-end 604 may provide various front-end
functionality. The front-end functionality may include, but is not
limited to, switching, amplifying, filtering, converting, etc.
[0044] In various embodiments, the antenna 616 may include one or
more directional and/or omnidirectional antennas, including a
dipole antenna, a monopole antenna, a patch antenna, a loop
antenna, a microstrip antenna, or any other type of antenna
suitable for transmission and/or reception of RF signals.
[0045] In various embodiments, the wireless communication device
600 may be, but is not limited to, a mobile telephone, a paging
device, a personal digital assistant, a text-messaging device, a
portable computer, a desktop computer, a base station, a subscriber
station, an access point, a radar, a satellite communication
device, or any other device capable of wirelessly
transmitting/receiving RF signals.
[0046] Those skilled in the art will recognize that the RF system
600 is given by way of example and that, for simplicity and
clarity, only so much of the construction and operation of the RF
system 600 as is necessary for an understanding of the embodiments
is shown and described. Various embodiments contemplate any
suitable component or combination of components performing any
suitable tasks in association with the RF system 600, according to
particular needs. Moreover, it is understood that the RF system 600
should not be construed to limit the types of devices in which
embodiments may be implemented.
[0047] Although certain embodiments have been illustrated and
described herein for purposes of description of the preferred
embodiment, it will be appreciated by those of ordinary skill in
the art that a wide variety of alternate and/or equivalent
embodiments or implementations calculated to achieve the same
purposes may be substituted for the embodiments shown and described
without departing from the scope of the present invention. Those
with skill in the art will readily appreciate that embodiments in
accordance with the present invention may be implemented in a very
wide variety of ways. This application is intended to cover any
adaptations or variations of the embodiments discussed herein.
Therefore, it is manifestly intended that embodiments in accordance
with the present invention be limited only by the claims and the
equivalents thereof.
* * * * *