U.S. patent application number 15/644831 was filed with the patent office on 2019-01-10 for package structure and manufacturing method thereof.
This patent application is currently assigned to Powertech Technology Inc.. The applicant listed for this patent is Powertech Technology Inc.. Invention is credited to Shang-Yu Chang Chien, Hung-Hsin Hsu, Han-Wen Lin, Nan-Chun Lin.
Application Number | 20190013214 15/644831 |
Document ID | / |
Family ID | 64904208 |
Filed Date | 2019-01-10 |
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United States Patent
Application |
20190013214 |
Kind Code |
A1 |
Lin; Han-Wen ; et
al. |
January 10, 2019 |
PACKAGE STRUCTURE AND MANUFACTURING METHOD THEREOF
Abstract
A manufacturing method of a package structure is described. The
method includes at least the following steps. A carrier is
provided. A semiconductor die and a sacrificial structure are
disposed on the carrier. The semiconductor die is electrically
connected to the bonding pads on the sacrificial structure through
a plurality of conductive wires. As encapsulant is formed on the
carrier to encapsulate the semiconductor die, the sacrificial
structure and the conductive wires. The carrier is debonded, and at
least a portion of the sacrificial structure is removed through a
thinning process. A redistribution layer is formed on the
semiconductor die and the encapsulant. The redistribution layer is
electrically connected to the semiconductor die through the
conductive wires.
Inventors: |
Lin; Han-Wen; (Hsinchu
County, TW) ; Hsu; Hung-Hsin; (Hsinchu County,
TW) ; Chang Chien; Shang-Yu; (Hsinchu County, TW)
; Lin; Nan-Chun; (Hsinchu County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Powertech Technology Inc. |
Hsinchu County |
|
TW |
|
|
Assignee: |
Powertech Technology Inc.
Hsinchu County
TW
|
Family ID: |
64904208 |
Appl. No.: |
15/644831 |
Filed: |
July 10, 2017 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 24/95 20130101;
H01L 2224/04042 20130101; H01L 2224/32145 20130101; H01L 23/50
20130101; H01L 25/50 20130101; H01L 2224/05624 20130101; H01L
2224/95001 20130101; H01L 2224/04105 20130101; H01L 2924/19106
20130101; H01L 23/49816 20130101; H01L 2224/27318 20130101; H01L
2225/06562 20130101; H01L 23/3128 20130101; H01L 2224/02381
20130101; H01L 2224/73265 20130101; H01L 2924/15311 20130101; H01L
2924/18165 20130101; H01L 2924/3511 20130101; H01L 25/0657
20130101; H01L 2224/2919 20130101; H01L 2224/83101 20130101; H01L
2924/00014 20130101; H01L 2224/02379 20130101; H01L 2224/48227
20130101; H01L 21/561 20130101; H01L 2224/13024 20130101; H01L
2224/83001 20130101; H01L 2224/83191 20130101; H01L 24/13 20130101;
H01L 24/48 20130101; H01L 24/85 20130101; H01L 2225/0651 20130101;
H01L 2225/0652 20130101; H01L 24/32 20130101; H01L 24/73 20130101;
H01L 2224/48111 20130101; H01L 2224/48465 20130101; H01L 2224/73253
20130101; H01L 2224/8385 20130101; H01L 2924/181 20130101; H01L
24/05 20130101; H01L 2224/27436 20130101; H01L 24/04 20130101; H01L
24/29 20130101; H01L 21/568 20130101; H01L 24/27 20130101; H01L
24/92 20130101; H01L 24/96 20130101; H01L 2224/48091 20130101; H01L
2224/85001 20130101; H01L 2924/19105 20130101; H01L 24/97 20130101;
H01L 24/83 20130101; H01L 2224/2732 20130101; H01L 2224/48091
20130101; H01L 2924/00014 20130101; H01L 2924/181 20130101; H01L
2924/00012 20130101; H01L 2924/00014 20130101; H01L 2224/45099
20130101; H01L 2224/73265 20130101; H01L 2224/32145 20130101; H01L
2224/48227 20130101; H01L 2924/00012 20130101; H01L 2224/05624
20130101; H01L 2224/73265 20130101; H01L 2224/32145 20130101; H01L
2924/00014 20130101; H01L 2224/48227 20130101; H01L 2924/00012
20130101; H01L 2224/05624 20130101; H01L 2924/3511 20130101; H01L
2924/00014 20130101; H01L 2924/00012 20130101; H01L 2924/3511
20130101; H01L 2924/00014 20130101; H01L 2224/29099 20130101; H01L
2924/00012 20130101; H01L 2924/00014 20130101; H01L 2224/29099
20130101; H01L 2224/2919 20130101; H01L 2924/0665 20130101; H01L
2924/00014 20130101 |
International
Class: |
H01L 21/56 20060101
H01L021/56; H01L 23/00 20060101 H01L023/00; H01L 25/065 20060101
H01L025/065 |
Claims
1. A manufacturing method of a package structure, comprising:
providing a carrier, disposing a semiconductor die and at least one
sacrificial structure on the carrier; electrically connecting the
semiconductor die to bonding pads on the sacrificial structure
through a plurality of conductive wires; forming an encapsulant on
the carrier to encapsulate the semiconductor die, the sacrificial
structure and the conductive wires; debonding the carrier, removing
at least a portion of the sacrificial structure through a thinning
process; and forming a redistribution layer on the semiconductor
die and the encapsulant, the redistribution layer is electrically
connected to the semiconductor die through the conductive
wires.
2. The manufacturing method of a package structure according to
claim 1, wherein the sacrificial structure is disposed on the
carrier, and the semiconductor die is disposed on the sacrificial
structure.
3. The manufacturing method of a package structure according to
claim 2, wherein a width of the sacrificial structure is greater
than a width of the semiconductor die.
4. The manufacturing method of a package structure according to
claim 2, wherein the redistribution layer is formed on the
semiconductor die and the encapsulant after the removal of the
sacrificial structure, and a plurality of passive components is
disposed on the redistribution layer.
5. The manufacturing method of a package structure according to
claim 1, wherein the thinning process removes a portion of the
semiconductor die to form a thinned semiconductor die.
6. The manufacturing method of a package structure according to
claim 1, wherein the bonding pads or the conductive wires are
revealed after the thinning process.
7. The manufacturing method of a package structure according to
claim 1, wherein a plurality of the sacrificial structures is
disposed on the carrier to surround the semiconductor die.
8. The manufacturing method of a package structure according to
claim 7, wherein the semiconductor die and the sacrificial
structures are disposed on a same plane and on a same surface of
the carriers.
9. The manufacturing method of a package structure according to
claim 7, further comprising: forming a plurality of passive
components on the sacrificial structures, wherein the encapsulant
is formed to encapsulate the passive components.
10. The manufacturing method of a package structure according to
claim 9, wherein the redistribution layer is formed on the
semiconductor die and the encapsulant after the removal of the
sacrificial structure, and the redistribution layer is electrically
connected to the semiconductor die and the passive components.
11. A package structure, comprising: an encapsulant having a top
surface and a bottom surface opposite to the top surface; a stacked
die embedded in the encapsulant; a plurality of bonding pads of a
sacrificial structure encapsulated by the encapsulant, wherein
connection terminals of the bonding pads are exposed on a top
surface of the encapsulant; a plurality of conductive wires
embedded in the encapsulant, each of the plurality of conductive
wires having one end coupled to the stacked die and another end
coupled to a terminal of the bonding pads opposite the connection
terminals; a redistribution layer, directly formed on a first
surface of the stacked die exposed through the encapsulant, the
connection terminals of the bonding pads, and the top surface of
the encapsulant, the redistribution layer is electrically connected
to the stacked die through the bonding pads and the conductive
wires, wherein the connection terminals of the bonding pads, the
first surface of the stacked die, and the top surface of the
encapsulant are coplanar to each other.
12. The package structure according to claim 11, further comprising
at least one passive component embedded in the encapsulant.
13. The package structure according to claim 11, further comprising
at least one passive component disposed on the redistribution
layer.
14. The package structure according to claim 11, wherein the
encapsulant has a first thickness, and the redistribution layer has
a second thickness smaller than the first thickness.
15. The package structure according to claim 14, wherein the
encapsulant provides a first rigidity, and the redistribution layer
provides a second rigidity, the first rigidity is greater than the
second rigidity.
16. (canceled)
17. The package structure according to claim 11, wherein the
stacked die comprises: a first die having a first surface exposed
through the encapsulant; a second die stacked on the first die
opposite to a side of the first surface, the second die cover
portions of the first die, and other portions of the first die not
covered by the second die contain die pads, the die pads of the
first die are electrically connected to the bonding pads through
the conductive wires.
18. The package structure according to claim 17, wherein the
stacked die further comprises: a third die stacked on the second
die, the third die cover portions of the second die, and other
portions of the second die not covered by the third die contain die
pads, the die pads of the second die are electrically connected to
the bonding pads through the conductive wires.
19. The package structure according to claim 11, further comprising
a plurality of conductive balls disposed on the redistribution
layer.
20. The package structure according to claim 19, wherein the
bonding pads are arranged with a first pitch and the conductive
balls are arranged with a second pitch, the second pitch is greater
than the first pitch.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0001] The present invention generally relates to a package
structure, in particular, to a manufacturing method of a package
structure using sacrificial structures for wire bonding.
2. Description of Related Art
[0002] In order for electronic product design to achieve being
light, slim, short, and small, semiconductor packaging technology
has kept progressing, in attempt to develop products that are
smaller in volume, lighter in weight, higher in integration, and
more competitive in market. For example, integrated fan-out
packages have become increasingly popular due to their compactness.
However, in current fan-out package designs, if a package requires
multi-chip stacking, two redistribution layers (RDL) and big
pillars are generally required to provide the connection. For such
package designs, the manufacturing process is usually complicated,
time consuming and an issue of warpage also exist. Therefore, a
simplified method/design having lower production cost is
desired.
SUMMARY OF THE INVENTION
[0003] The invention provides a package structure and a
manufacturing method thereof, which uses sacrificial structures to
fix the location of a wire for wire bonding. The method effectively
reduces the size and manufacturing cost of the package, and
overcomes the issue of wafer or panel warpage.
[0004] The invention provides a manufacturing method of a package
structure. The method includes at least the following steps. A
carrier is provided. A semiconductor die and a sacrificial
structure are disposed on the carrier. The semiconductor die is
electrically connected to bonding pads on the sacrificial structure
through a plurality of conductive wires. As encapsulant is formed
on the carrier to encapsulate the semiconductor die, the
sacrificial structure and the conductive wires. The carrier is
debonded, and the sacrificial structure is removed through a
thinning process to reveal the bonding pads or the conductive
wires. A redistribution layer is formed on the semiconductor die
and the encapsulant. The redistribution layer is electrically
connected to the semiconductor die through the conductive
wires.
[0005] The invention further provides a package structure including
an encapsulant, a stacked die, a plurality of bonding pads, a
plurality of conductive wires, and a redistribution layer. The
encapsulant has a top surface and a bottom surface opposite to the
top surface. The stacked die is embedded in the encapsulant. The
bonding pads are embedded in the encapsulant, wherein the bonding
pads are exposed on a top surface of the encapsulant. The
conductive wires are embedded in the encapsulant, wherein the
stacked die is electrically connected to the bonding pads through
the conductive wires. The redistribution layer is disposed on the
stacked die and on the top surface of the encapsulant, wherein the
redistribution layer is electrically connected to the stacked die
through the bonding pads and the conductive wires.
[0006] Based on the above, a sacrificial structure is used to fix
the position of the conductive wires. As such, when removing the
sacrificial structure, the precise location of the wire or weld may
be provided for further connection. In addition, a thickness of the
semiconductor die may be effectively controlled during the thinning
process, thus an overall size of the package structure may be
reduced. Furthermore, with the presence of the sacrificial
structure, an area ratio between the dies and the encapsulant is
decreased. Thus, the issue of wafer or panel warpage may be
resolved. Overall, the simplicity of the manufacturing process of
the package structure may be realized, thereby reducing the
manufacturing cost.
[0007] To make the above features and advantages of the present
invention more comprehensible, several embodiments accompanied with
drawings are described in detail as follows.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The accompanying drawings are included to provide a further
understanding of the invention, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the invention and, together with the description,
serve to explain the principles of the invention.
[0009] FIG. 1A to FIG. 1G are schematic cross-sectional views
illustrating a manufacturing method of a package structure
according to an embodiment of the invention.
[0010] FIG. 2A to FIG. 2G are schematic cross-sectional views
illustrating a manufacturing method of a package structure
according to an embodiment of the invention.
DESCRIPTION OF THE EMBODIMENTS
[0011] Reference will now be made in detail to the present
preferred embodiments of the invention, examples of which are
illustrated in the accompanying drawings. Wherever possible, the
same reference numbers are used in the drawings and the description
to refer to the same or like parts.
[0012] FIG. 1A to FIG. 1G are schematic cross-sectional views
illustrating a manufacturing method of a package structure
according to an embodiment of the invention. Referring to FIG. 1A,
a carrier 102 is provided. The carrier 102 may be a glass substrate
or a glass supporting board. In some embodiments, other suitable
substrate material may be adapted as the carrier 102 as long as the
material is able to withstand the subsequent processes while
carrying the package structure formed thereon.
[0013] The sacrificial structures 104B are disposed on the carrier
102. The sacrificial structures 104B are, for example, a
sacrificial layer to be removed in a subsequent process. Thus, a
material of the sacrificial layer is not particularly limited, as
long as it can be removed through a thinning process described
thereafter. The sacrificial structures 104B are disposed on the
carrier 102 through an adhesive layer 103 located on the carrier
102. In some embodiments, the adhesive layer 103 may be a die
attach film or formed from adhesive materials including an epoxy
resin. The adhesive layer 103 may be formed by methods such as
coating, inkjet printing, film attaching or other suitable methods
for providing a structural support to eliminate the need for
mechanical clamping between the sacrificial structures 104B and the
carrier 102.
[0014] The semiconductor die 104A is disposed on the carrier 102,
and located on the sacrificial structures 104B. In the present
embodiment, the semiconductor die 104A is, for example stacked dies
that comprise at least a bottom semiconductor die and a top
semiconductor die stacked on top of each other. For instance, as
shown in FIG. 1A, the semiconductor die 104A includes a first
semiconductor die 104A-1, a second semiconductor die 104A-2 and a
third semiconductor die 104A-3 stacked on top of each other. The
first semiconductor die 104A-1 serve as the bottom semiconductor
die, while the third semiconductor die 104A-3 serve as the top
semiconductor die, while the second semiconductor die 104A-2 is
sandwiched therebetween. However, it construes no limitation in the
invention. The number of stacked dies in the semiconductor die 104A
is not particularly limited. In some embodiments, a die attach film
(DAF; not illustrated) may be disposed between each of the stacked
dies to enhance their adhesion. Furthermore, in the present
embodiment, the semiconductor die 104A is, for example, an ASIC
(Application-Specific Integrated Circuit). However, it construes no
limitation in the invention. Other suitable active devices may also
be utilized as the semiconductor die 104A.
[0015] As shown in FIG. 1A, a width W2 of the sacrificial structure
104B is greater than a width W1 of the semiconductor die 104A. In
the case for stacked dies, the width W2 of the sacrificial
structure 104B is greater than a width of each of the semiconductor
dies (104A-1, 104A-2 and 104A-3). The semiconductor die 104A or the
stacked dies each have a first surface Y1 facing the carrier 102
and a second surface Y2 facing away from the carrier 102.
Furthermore, bonding pads 105 are provided on the sacrificial
structures 104B, and provided on the second surfaces Y2 of the
semiconductor die 104A (stacked dies). The bonding pads 105 are,
for example, aluminum pads or any other suitable material used for
wire bonding. In some embodiments, the bonding pads 105 can be
embedded within the sacrificial structures 104B.
[0016] Furthermore, as shown in FIG. 1A, a plurality of conductive
wires 106 is provided to electrically connect the bonding pads 105
of the semiconductor die 104A to the bonding pads 105 of the
sacrificial structures 104B. The conductive wires 106 are, for
example, used for wire bonding, and have a curved three-dimensional
structure. In some embodiments, the conductive wires 106 are formed
after stacking several dies in a group. For example, for multi-die
stacking, the conductive wires 106 are used to provide electrical
connection after two to four dies are stacked. For instance, in the
embodiment shown in FIG. 1A, after disposing the first
semiconductor die 104A-1 on the sacrificial structures 104B, and
disposing the second semiconductor die 104A-2 on the first
semiconductor die 104A-1, the conductive wires 106 are used to
electrically connect the bonding pads 105 on the stacked
semiconductor dies (104A-1 and 104A-2) to the bonding pads 105 on
the sacrificial structure 104B. The process is repeated until all
dies are stacked and the electrical connection is established. In
some alternative embodiments, the conductive wires 106 are formed
after all dies (104A-1, 104A-2 and 104A-3) are stacked.
[0017] Referring to FIG. 1B, after wire bonding, an encapsulant 108
is formed on the carrier 102 to encapsulate the semiconductor die
104A, the sacrificial structure 104B and the conductive wires 106.
The semiconductor die 104A, the sacrificial structures 104B and the
conductive wires 106 are completely encapsulated by the encapsulant
108. In some embodiments, the encapsulant 108 may be a molding
compound formed by molding processes. However, in some alternative
embodiments, the encapsulant 108 may be formed by an insulating
material such as epoxy or other suitable resins. In general, when
an area ratio of a die to an encapsulant is low, a problem of wafer
or panel warpage may occur. As shown in FIG. 1B, by having the
sacrificial structure 104B serving as a base structure, an area
ratio of the dies (sacrificial structure as dummy die plus the
semiconductor die) to the encapsulant 108 is increased. As such, an
issue of wafer or panel warpage may be resolved.
[0018] Referring to FIG. 1C, the carrier 102 is debonded. That is,
the carrier 102 is separated from the encapsulant 108, the
semiconductor die 104A, and sacrificial structures 104B. In some
alternative embodiments, in order to enhance the releasability of
the semiconductor die 104A and sacrificial structures 104B from the
carrier 102, a de-bonding layer (not illustrated) may be disposed
on the carrier 102 before disposing the dies (104A/104B) on the
carrier 102. The de-bonding layer is, for example, a light to heat
conversion (LTHC) release layer or other suitable release
layers.
[0019] Referring to FIG. 1D, after debonding the carrier 102, the
sacrificial structures 104B are removed by a thinning process to
reveal/expose the conductive wires 106. Specifically, connection
terminals CT of the conductive wires 106 are exposed. In the
present embodiment, connection terminals CT may refer to end
portions of the conductive wires 106 that are available for further
connection. However, it construes no limitation in the invention.
In alternative embodiments, the connection terminals CT can be the
bonding pads 105 or studs of the conductive wires 106 that are used
for further connection. That is, the connection terminals CT are
generally treated as "connection points" that connect the
conductive wires 106 to a redistribution layer 110 formed
thereafter. Wherein, the bonding pads 105 or studs of the
conductive wires 106 may have a surface area greater than an area
of the cross section of the conductive wires 106.
[0020] Referring back to FIG. 1D, the thinning process may be
performed through mechanical grinding, chemical mechanical
polishing (CMP), or other suitable processes. After the thinning
process, the connection terminals CT of the revealed conductive
wires 106 are coplanar with a first surface S1 of the semiconductor
die 104A. In some embodiments, the thinning process may remove
portions of the semiconductor die 104A to form a thinned
semiconductor die 104A. For example, in the present embodiment, a
portion of the first semiconductor die 104A-1 (or bottom
semiconductor die) is partially removed by the thinning process, so
that the connection terminals CT (of the conductive wires 106) are
coplanar with the first surface S of the first semiconductor die
104A-1 (bottom semiconductor die). In other words, a thickness of
the first semiconductor die 104A-1 is reduced. In particular,
referring to FIG. 1C, the first semiconductor die 104A-1 have a
thickness of T1 before the thinning process, whereas in FIG. 1D, a
thickness of the first semiconductor die 104A-1 reduces to T2 after
the thinning process. From the present embodiment, the thickness of
the semiconductor die 104 may be reduced during the thinning
process. However, it construes no limitation in the invention. In
other embodiments, the thickness of the semiconductor die 104A does
not change after the thinning process. In alternative embodiments,
the thickness of the semiconductor die 104A may be adjusted based
on requirement during the thinning process.
[0021] As shown in FIG. 1D, the bonding pads 105 on the sacrificial
structures 104B are removed by the thinning process to reveal the
conductive wires 106 underneath. That is, the end portions of the
conductive wires 106 are treated as the connection terminals CT.
However, it construes no limitation in the invention. In
alternative embodiments, the bonding pads 105 on the sacrificial
structures 104B remain after the thinning process. In such
embodiments, the thinning process is performed to reveal the
bonding pads 105 on the sacrificial structures 104B, and the
revealed portions of the bonding pads 105 serve as the connection
terminals CT. Furthermore, the sacrificial structures 104B may be
completely removed by the thinning process or residual amounts of
the sacrificial structures 104B may remain after the thinning
process.
[0022] Referring to FIG. 1E, after removing the sacrificial
structures 104B through the thinning process, a redistribution
layer 110 is formed on the semiconductor die 104A and the
encapsulant 108. The redistribution layer 110 may include a
plurality of conductive elements 110A and a plurality of dielectric
layers 110B alternately formed and stacked on top of each other. As
illustrated in FIG. 1E, the redistribution layer 110 includes four
dielectric layers 110B. However, the number of the dielectric layer
110B is not limited and may be adjusted based on circuit design.
The conductive elements 110A may include a plurality of trace
layers and a plurality of interconnect structures connecting the
trace layers. Furthermore, in the present embodiment, the
redistribution layer 110 is formed on the first surface S1 of the
semiconductor die 104A (stacked die). The redistribution layer 110
is electrically connected to the semiconductor die 104A through the
conductive wires 106 at the connection terminals CT. In particular,
the conductive wires 106 are electrically connected to the
conductive elements 110A of the redistribution layer 110 through
the connection terminals CT. Conductive terminals 118 are then
formed on the redistribution layer 110, and being electrically
connected to the conductive elements 110A. The conductive terminals
118 may be a plurality of under-ball metallurgy (UBM) patterns for
ball mount or connection pads for mounting of passive
components.
[0023] Referring to FIG. 1F, after the formation of the
redistribution layer 110 and the conductive terminals 118, a
plurality of conductive balls 120 are placed onto the conductive
terminals 118, and one or more passive components 115 may be
mounted on the conductive terminals 118. The conductive terminals
118 and the conductive balls 120 may, for example, be formed by a
ball placement process and a reflow process. The passive components
115 may be mounted on the conductive terminals 118 through a
soldering process. Examples of the passive components 115 include
capacitors, resistors, inductors, fuses, or antennas. However, they
construe no limitation in the invention. After placing the
conductive balls 120 and the passive components 115 on the
conductive terminals 118, a dicing or singulation process is
performed on the package structure illustrated in FIG. 1F to render
a plurality of individual packages 100 as shown in FIG. 1G. The
dicing process is, for example, performed at the dicing line DL for
singulation of the individual packages 100.
[0024] FIG. 2A to FIG. 2G are schematic cross-sectional views
illustrating a manufacturing method of a package structure
according to an embodiment of the invention. The embodiments shown
in FIG. 2A to FIG. 2G are similar to the embodiments shown in FIG.
1A to FIG. 1G, therefore, the same reference numerals are used to
refer to the same or like parts, and their detailed descriptions
are omitted herein. The difference between the embodiments shown in
FIG. 2A to FIG. 2G and the embodiments shown in FIG. 1A to FIG. 1G
is in the position/design of the sacrificial structures 104B.
[0025] As shown in FIG. 2A, the semiconductor die 104A and at least
one sacrificial structure 104B are disposed on the carrier 102. In
the exemplary embodiment, a plurality of the sacrificial structures
104B are disposed on the carrier 102 to surround the semiconductor
die 104A. Moreover, the semiconductor die 104A and the sacrificial
structures 104B are disposed on a same plane and on a same surface
102A of the carrier 102. In the present embodiment, a width (W2/W3)
of the sacrificial structures 102B is smaller than a width W1 of
the semiconductor die 104A. The plurality of sacrificial structures
102B may have different widths W2 and W3. However, both of the
widths W2 and W3 are smaller than the width W1 of the semiconductor
die 104A. Furthermore, a thickness K2 of the sacrificial structures
104B is smaller than a thickness K1 of the semiconductor dies 104A.
The thickness K1 of the semiconductor dies 104A refers to the
thickness of the first semiconductor die 104A-1 (bottom
semiconductor die) of the stacked dies. In the present embodiment,
the sacrificial structures 104B is also a sacrificial layer that is
removed thereafter. In other words, a thickness difference X1
between the semiconductor die 104A and the sacrificial structures
104B (K1-K2) will determine a thickness of a thinned semiconductor
die 104A formed thereafter.
[0026] Similar to the embodiments shown in FIG. 1A, bonding pads
105 may be formed on the semiconductor dies 104A and the
sacrificial structures 104B to allow for wire bonding. The wire
bonding process is, for example, performed after the stacking of
several dies in a group, or performed after stacking of all of the
dies. In addition, passive components 115 may be disposed on the
sacrificial structures 104B. For example, the passive components
115 may be adjacent to the bonding pads 105 and may be disposed on
the same surface of the sacrificial structures 104B. Furthermore, a
plurality of conductive wires 106 is provided to electrically
connect the bonding pads 105 of the semiconductor die 104A to the
bonding pads 105 of the sacrificial structures 104B.
[0027] Referring to FIG. 2B, similar to the embodiment shown in
FIG. 1B, an encapsulant 108 is formed on the carrier 102 to
encapsulate the semiconductor die 104A, the sacrificial structure
104B and the conductive wires 106. However, in the embodiment shown
in FIG. 2B, the encapsulant 108 further encapsulates the passive
components 115. The semiconductor die 104A, the sacrificial
structures 104B, the conductive wires 106 and the passive
components 115 are completely encapsulated by the encapsulant 108.
As shown in FIG. 2B, by having the sacrificial structures 104B
surrounding the semiconductor die 104A, an area ratio of the die
(semiconductor dies and sacrificial dummy dies) to the encapsulant
108 is increased. As such, an issue of wafer or panel warpage may
be resolved.
[0028] Referring to FIG. 2C, after formation of the encapsulant
108, the carrier 102 are debonded. That is, the carrier 102 is
separated from the encapsulant 108, the semiconductor die 104A, and
sacrificial structures 104B. In some alternative embodiments, in
order to enhance the releasability of the semiconductor die 104A
and sacrificial structures 104B from the carrier 102, a de-bonding
layer (not illustrated) may be disposed on the carrier 102 before
disposing the dies (104A/104B) on the carrier 102. The de-bonding
layer is, for example, a light to heat conversion (LTHC) release
layer or other suitable release layers.
[0029] Referring to FIG. 2D, after debonding the carrier 102, the
sacrificial structures 104B are removed by a thinning process to
reveal/expose the bonding pads 105 on the sacrificial structures
104B. That is, a revealed portion of the bonding pads 105 serve as
the connection terminals CT. However, it construes no limitation in
the invention. In alternative embodiments, the connection terminals
CT can be the end portions (or studs) of the conductive wires 106.
That is, the thinning process is performed to reveal/expose the end
portions of the conductive wires 106. As noted above, connection
terminals CT are generally treated as "connection points" that
connect the conductive wires 106 to a redistribution layer 110
formed thereafter. Therefore, the connection terminals CT will
apply to all embodiments, and its position may be altered depending
on which portion is revealed (wires/pads) for connection.
[0030] As shown in FIG. 2D, after the thinning process, the
connection terminals CT of the bonding pads 105 are coplanar with a
first surface S1 of the semiconductor die 104A. In particular, a
portion of the first semiconductor die 104A-1 (or bottom
semiconductor die) is removed by the thinning process, so that the
connection terminals CT are coplanar with the first surface S1 of
the first semiconductor die 104A-1 (bottom semiconductor die).
Moreover, a thickness 104T of the thinned semiconductor die (first
semiconductor die 104A-1) will correspond to a thickness difference
X1 (see FIG. 2A) between the semiconductor die 104A (first
semiconductor die 104A-1) and the sacrificial structure 104B before
the thinning process.
[0031] Referring to FIG. 2E, after removing the sacrificial
structures 104B through the thinning process, a redistribution
layer 110 is formed on the semiconductor die 104A and the
encapsulant 108. The redistribution layer 110 of FIG. 2E is similar
to the redistribution layer 110 of FIG. 1E, hence its detailed
description is omitted herein. In the present embodiment, the
redistribution layer 110 is electrically connected to the
semiconductor die 104A through the conductive wires 106 at the
connection terminals CT. In particular, the conductive wires 106
are electrically connected to the conductive elements 110A of the
redistribution layer 110 through the connection terminals CT (of
bonding pads 105). Conductive terminals 118 are then formed on the
redistribution layer 110, and being electrically connected to the
conductive elements 110A.
[0032] Referring to FIG. 2F, after the formation of the
redistribution layer 110 and the conductive terminals 118, a
plurality of conductive balls 120 are placed onto the conductive
terminals 118. The conductive terminals 118 and the conductive
balls 120 may, for example, be formed by a ball placement process
and a reflow process. After placing the conductive balls 120 on the
conductive terminals 118, a dicing or singulation process is
performed on the package structure illustrated in FIG. 2F to render
a plurality of individual packages 100' as shown in FIG. 2G. The
dicing process is, for example, performed at the dicing line DL for
singulation of the individual packages 100'.
[0033] Referring to FIG. 2G, the individual packages 100' includes
an encapsulant 108, a stacked die 104A, a plurality of bonding pads
105, a plurality of conductive wires 106, a redistribution layer
110 and a plurality of conductive balls 120. The encapsulant 108
has a top surface 108A and a bottom surface 108B opposite to the
top surface 108A. The stack die 104A is embedded in the encapsulant
108. The bonding pads 105 are embedded in the encapsulant 108,
wherein connection terminals CT of the bonding pads 105 are exposed
on a top surface 108A of the encapsulant 108. The conductive wires
106 are embedded in the encapsulant 108, wherein the stacked die
104A is electrically connected to the bonding pads 105 through the
conductive wires. The redistribution layer 110 is disposed on the
stacked die 104A and on the top surface 108A of the encapsulant
108, wherein the redistribution layer 110 is electrically connected
to the stacked die 104A through the bonding pads 105 and the
conductive wires 106.
[0034] In the exemplary embodiment, the stacked die (semiconductor
die 104A) has a first surface S1 exposed through the encapsulant
108. The connection terminals CT of the bonding pads 105 are
coplanar with the first surface S1 of the stacked die 104A and the
top surface 108A of the encapsulant 108. Furthermore, the stacked
die 104A may include a first die (first semiconductor die) 104A-1,
a second die (second semiconductor die) 104A-2 and a third die
(third semiconductor die) 104A-3. The first die 104A-1 has the
first surface S1 exposed through the encapsulant 108. The second
die 104A-2 is stacked on the first die 104A-1 opposite to a side of
the first surface S1. The second die 104A-2 cover portions of the
first die 104A-1, and other portions of the first die 104A-1 not
covered by the second die 104A-2 contain die pads DP (bonding pads
105). The die pads DP of the first die 104A-1 are electrically
connected to the bonding pads 105 through the conductive wires 106.
In addition, the third die 104A-3 is stacked on the second die
104A-2, the third die 104A-3 cover portions of the second die
104A-2, and other portions of the second die 104A-2 not covered by
the third die 104A-3 contain die pads DP, the die pads DP of the
second die 104A-2 are electrically connected to the bonding pads
105 through the conductive wires 106.
[0035] In the embodiment shown in FIG. 2G, the individual packages
100' further includes at least one passive component 115 embedded
in the encapsulant 108. However, it construes no limitation in the
invention. In alternative embodiments, the passive components 115
may be disposed on the redistribution layer 110. Furthermore, in
the exemplary embodiment, the encapsulant 108 has a first thickness
108T, and the redistribution layer 110 has a second thickness 110T
smaller than the first thickness 108T. That is, the encapsulant 108
provides a first rigidity, and the redistribution layer 110
provides a second rigidity, wherein the first rigidity is greater
than the second rigidity. In addition, the bonding pads 105 are
arranged with a first pitch P and the conductive balls 120 are
arranged with a second pitch P2, the second pitch P2 is greater
than the first pitch P1. That is, the individual packages 100' are
directed to fan-out packages. The first pitch P and the second
pitch P2 is calculated based on a center position of the bonding
pads 105 and the conductive balls 120.
[0036] In the embodiments shown above, the sacrificial structures
are used to fix the position of the conductive wires. As such, when
removing the sacrificial structure, the precise location of the
wire or weld may be provided for further connection. Furthermore, a
thickness of the semiconductor die may be effectively controlled
during the thinning process, thus an overall size of the package
structure may be reduced. In addition, with the presence of the
sacrificial structure, an area ratio between the dies and the
encapsulant is decreased. Thus, the issue of wafer or panel warpage
may be resolved. Accordingly, the simplicity of the manufacturing
process of the package structure may be realized, thereby reducing
the overall manufacturing cost.
[0037] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present invention without departing from the scope or spirit of the
invention. In view of the foregoing, it is intended that the
present invention covers modifications and variations of this
invention provided fall within the scope of the following claims
and their equivalents.
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