U.S. patent application number 15/717953 was filed with the patent office on 2018-04-26 for manufacturing method of package-on-package structure.
This patent application is currently assigned to Powertech Technology Inc.. The applicant listed for this patent is Powertech Technology Inc.. Invention is credited to Hsien-Wen Hsu, Hung-Hsin Hsu, Yuan-Fu Lan, Chi-An Wang.
Application Number | 20180114782 15/717953 |
Document ID | / |
Family ID | 61969764 |
Filed Date | 2018-04-26 |
United States Patent
Application |
20180114782 |
Kind Code |
A1 |
Wang; Chi-An ; et
al. |
April 26, 2018 |
MANUFACTURING METHOD OF PACKAGE-ON-PACKAGE STRUCTURE
Abstract
A manufacturing method of a package-on package structure
including at least the following steps is provided. A die is bonded
on a first circuit carrier. A spacer is disposed on the die. The
spacer and the first circuit carrier are connected through a
plurality of conductive wires. An encapsulant is formed to
encapsulate the die, the spacer and the conductive wires. A
thickness of the encapsulant is reduced until at least a portion of
each of the conductive wires is removed to form a first package
structure. A second package structure is stacked on the first
package structure. The second package structure is electrically
connected to the conductive wires.
Inventors: |
Wang; Chi-An; (Hsinchu
County, TW) ; Hsu; Hung-Hsin; (Hsinchu County,
TW) ; Lan; Yuan-Fu; (Hsinchu County, TW) ;
Hsu; Hsien-Wen; (Hsinchu County, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Powertech Technology Inc. |
Hsinchu County |
|
TW |
|
|
Assignee: |
Powertech Technology Inc.
Hsinchu County
TW
|
Family ID: |
61969764 |
Appl. No.: |
15/717953 |
Filed: |
September 28, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62410851 |
Oct 21, 2016 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01L 21/4853 20130101;
H01L 23/3128 20130101; H01L 2224/16227 20130101; H01L 2224/29339
20130101; H01L 2224/85181 20130101; H01L 2225/1088 20130101; H01L
23/49 20130101; H01L 2224/73265 20130101; H01L 24/29 20130101; H01L
21/56 20130101; H01L 2225/1041 20130101; H01L 2224/29139 20130101;
H01L 23/49816 20130101; H01L 23/49827 20130101; H01L 2225/1035
20130101; H01L 23/49833 20130101; H01L 24/85 20130101; H01L 23/4334
20130101; H01L 23/5384 20130101; H01L 24/08 20130101; H01L
2224/32245 20130101; H01L 2224/45147 20130101; H01L 2224/85186
20130101; H01L 2924/15311 20130101; H01L 24/97 20130101; H01L
2924/1433 20130101; H01L 2924/1533 20130101; H01L 25/0657 20130101;
H01L 2224/16235 20130101; H01L 2224/32225 20130101; H01L 2224/48091
20130101; H01L 21/563 20130101; H01L 25/105 20130101; H01L 21/486
20130101; H01L 21/565 20130101; H01L 24/48 20130101; H01L
2224/45144 20130101; H01L 2224/48227 20130101; H01L 2224/48235
20130101; H01L 23/3121 20130101; H01L 2924/181 20130101; H01L
2224/08245 20130101; H01L 2224/16237 20130101; H01L 24/27 20130101;
H01L 2224/13147 20130101; H01L 2225/1023 20130101; H01L 23/50
20130101; H01L 24/45 20130101; H01L 2224/2919 20130101; H01L
23/49811 20130101; H01L 24/13 20130101; H01L 2224/13023 20130101;
H01L 2224/29294 20130101; H01L 2224/73251 20130101; H01L 23/49838
20130101; H01L 24/83 20130101; H01L 24/92 20130101; H01L 24/73
20130101; H01L 24/16 20130101; H01L 24/32 20130101; H01L 2924/1431
20130101; H01L 2224/83101 20130101; H01L 2225/1094 20130101; H01L
24/11 20130101; H01L 2224/03 20130101; H01L 2224/0401 20130101;
H01L 23/42 20130101; H01L 24/03 20130101; H01L 2224/73253 20130101;
H01L 24/80 20130101; H01L 2224/92222 20130101; H01L 21/4889
20130101; H01L 2224/04042 20130101; H01L 23/04 20130101; H01L
2224/92225 20130101; H01L 2225/1058 20130101; H01L 25/50 20130101;
H01L 2224/73265 20130101; H01L 2224/32225 20130101; H01L 2224/48227
20130101; H01L 2924/00012 20130101; H01L 2224/48091 20130101; H01L
2924/00014 20130101; H01L 2924/15311 20130101; H01L 2224/73265
20130101; H01L 2224/32225 20130101; H01L 2224/48227 20130101; H01L
2924/00 20130101; H01L 2224/73251 20130101; H01L 2224/08 20130101;
H01L 2224/16 20130101; H01L 2224/45144 20130101; H01L 2924/00014
20130101; H01L 2224/45147 20130101; H01L 2924/00014 20130101; H01L
2224/85181 20130101; H01L 2924/00014 20130101; H01L 2224/85186
20130101; H01L 2924/00014 20130101; H01L 2224/2919 20130101; H01L
2924/00014 20130101; H01L 2224/83101 20130101; H01L 2924/00014
20130101; H01L 2224/29339 20130101; H01L 2924/00014 20130101; H01L
2224/29294 20130101; H01L 2924/00014 20130101; H01L 2224/92222
20130101; H01L 2224/80 20130101; H01L 2924/15311 20130101; H01L
2224/73265 20130101; H01L 2224/32225 20130101; H01L 2224/48227
20130101; H01L 2924/00012 20130101 |
International
Class: |
H01L 25/10 20060101
H01L025/10; H01L 23/498 20060101 H01L023/498; H01L 23/49 20060101
H01L023/49; H01L 21/56 20060101 H01L021/56; H01L 25/00 20060101
H01L025/00 |
Claims
1. A manufacturing method of a package-on-package (POP) structure,
comprising: bonding a die on a first circuit carrier; disposing a
spacer on the die; connecting the spacer and the first circuit
carrier through a plurality of conductive wires; forming an
encapsulant to encapsulate the die, the spacer and the conductive
wires; reducing a thickness of the encapsulant until at least a
portion of each of the conductive wires are removed to form a first
package structure; and stacking a second package structure on the
first package structure, wherein the second package structure is
electrically connected to the conductive wires.
2. The manufacturing method of a POP structure according to claim
1, wherein the die is electrically connected to the first circuit
carrier through flip-chip bonding.
3. The manufacturing method of a POP structure according to claim
1, wherein the spacer is bonded to the die through an adhesive
layer.
4. The manufacturing method of a POP structure according to claim
1, wherein the conductive wires are formed through a wire
bonder.
5. The manufacturing method of a POP structure according to claim
1, wherein the spacer comprises a second circuit carrier, the
conductive wires are connected between the second circuit carrier
and the first circuit canier before reducing the thickness of the
encapsulant.
6. The manufacturing method of a POP structure according to claim
5, wherein each of the conductive wires comprises a first welding
segment connected to the first circuit carrier and a second welding
segment connected to the spacer before reducing the thickness of
the encapsulant, the conductive wires are connected from the first
circuit carrier through the first welding segments to the spacer
through the second welding segments.
7. The manufacturing method of a POP structure according to claim
6, wherein an angle between the first welding segment of each of
the conductive wires and the first circuit carrier is greater than
an angle between the second welding segment of each of the
conductive wires and the spacer before reducing the thickness of
the encapsulant.
8. The manufacturing method of a POP structure according to claim
6, wherein each of the conductive wires further comprises a
sacrificial segment connecting between the first welding segment
and the second welding segment before reducing the thickness of the
encapsulant, when reducing the thickness of the encapsulant, the
sacrificial segments of the conductive wires are removed.
9. The manufacturing method of a POP structure according to claim
8, wherein after reducing the thickness of the encapsulant, a
portion of each of the first welding segments of the conductive
wires and a portion of each of the second welding segments of the
conductive wires are exposed by the encapsulant.
10. The manufacturing method of a POP structure according to claim
8, wherein after the sacrificial segments of the conductive wires
are removed, the spacer is electrically floated.
11. The manufacturing method of a POP structure according to claim
8, wherein the second package structure comprises a plurality of
conductive terminals, each of the conductive terminals of the
second package structure is disposed on one of the first welding
segments of the conductive wires exposed by the encapsulant
respectively.
12. The manufacturing method of a POP structure according to claim
1, wherein the spacer comprises a conductive plate.
13. The manufacturing method of a POP structure according to claim
12, wherein the spacer is bonded to the die through a thermal
adhesive layer.
14. The manufacturing method of a POP structure according to claim
12, wherein after reducing the thickness of the encapsulant, a
surface of the spacer is exposed from the encapsulant.
15. The manufacturing method of a POP structure according to claim
12, wherein each of the conductive wires comprises a welding
segment connected to the first circuit carrier and a sacrificial
segment connected between the welding segment and the spacer before
reducing the thickness of the encapsulant, the conductive wires are
connected from the first circuit carrier through the welding
segment to the spacer through the sacrificial segment.
16. The manufacturing method of a POP structure according to claim
15, wherein an angle between the welding segment of each of the
conductive wires and the first circuit carrier is greater than an
angle between the sacrificial segment of each of the conductive
wires and the spacer before reducing the thickness of the
encapsulant.
17. The manufacturing method of a POP structure according to claim
15, wherein when reducing the thickness of the encapsulant, the
sacrificial segments of the conductive wires are removed.
18. The manufacturing method of a POP structure according to claim
15, wherein after reducing the thickness of the encapsulant, a
portion of each of the welding segments of the conductive wires are
exposed by the encapsulant.
19. The manufacturing method of a POP structure according to claim
15, wherein after the sacrificial segments of the conductive wires
are removed, the spacer is electrically floated.
20. The manufacturing method of a POP structure according to claim
15, wherein the second package structure comprises a plurality of
conductive terminals, each of the conductive terminals of the
second package structure is disposed on one of the welding segments
exposed by the encapsulant respectively.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the priority benefit of U.S.
provisional application Ser. No. 62/410,851, filed on Oct. 21,
2016. The entirety of the above-mentioned patent application is
hereby incorporated by reference herein and made a part of the
specification.
BACKGROUND OF THE INVENTION
1. Field of the Invention
[0002] The present invention generally relates to a manufacturing
method of a package structure, and more particularly relates to a
manufacturing method of a package-on-package (POP) structure.
2. Description of Related Art
[0003] 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 the market. For example, 3D stacking
technologies such as POP have been developed to meet the
requirements of higher packaging densities. As such, how to achieve
a thinner POP structure with lower manufacturing cost has become a
challenge to researchers in the field.
SUMMARY OF THE INVENTION
[0004] The disclosure provides a manufacturing method of a
package-on-package (POP) structure, which reduces the overall
thickness and the manufacturing cost thereof.
[0005] The disclosure provides a manufacturing method of a POP
structure. The method includes at least the following steps. A die
is bonded on a first circuit carrier. A spacer is disposed on the
die. The spacer and the first circuit carrier are connected through
a plurality of conductive wires. An encapsulant is formed to
encapsulate the die, the spacer and the conductive wires. A
thickness of the encapsulant is reduced until at least a portion of
each of the conductive wires is removed to form a first package
structure. A second package structure is stacked on the first
package structure. The second package structure is electrically
connected to the conductive wires.
[0006] Based on the above, the spacer disposed on the die is
conducive to form the conductive wires. In addition, since the
thickness of the encapsulant is reduced and also at least a portion
of each of the conductive wires is removed to form a first package
structure, the rest portion of the conductive wires in the
encapsulant may serve as the electrical connecting path between the
first package structure and the second package structure. In other
word, it is unnecessary to dispose additional interposer between
the first package structure and the second package structure for
electrical connection. Hence, the overall thickness of the POP
structure may be reduced and the lower manufacturing costs may be
achieved.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] The accompanying drawings are included to provide a further
understanding of the disclosure, and are incorporated in and
constitute a part of this specification. The drawings illustrate
embodiments of the disclosure and, together with the description,
serve to explain the principles of the disclosure.
[0008] FIG. 1A to FIG. 1F are schematic cross-sectional views
illustrating manufacturing method of a POP structure according to
an embodiment of the disclosure.
[0009] FIG. 2A to FIG. 2F are schematic cross-sectional views
illustrating manufacturing method of a POP structure according to
another embodiment of the disclosure.
DESCRIPTION OF THE EMBODIMENTS
[0010] Reference will now be made in detail to the present
preferred embodiments of the disclosure, 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.
[0011] FIG. 1A to FIG. 1F are schematic cross-sectional views
illustrating manufacturing method of a POP structure according to
an embodiment of the disclosure. Referring to FIG. 1A, a first
circuit carrier 110 is provided. The first circuit carrier 110 may
have a top surface S1 and a bottom surface S2 opposite to the top
surface S1. For example, the first circuit carrier 110 may include
a core layer 112, a top circuit layer 114 disposed on the top
surface S1 and the bottom circuit layer 116 disposed on the bottom
surface S2 of the first circuit carrier 110. The core layer 112 is
disposed between and electrically connects the top circuit layer
114 and the bottom circuit layer 116. In some embodiments, the top
circuit layer 114 and the bottom circuit layer 116 may respectively
include a plurality of conductive pads 114a and 116a used for
further electrical connection. Moreover, the conductive pads 114a
and the conductive pads 116a may be formed by the same material and
the same process such as using copper, solder, gold, nickel, or the
like through photolithography and etching processes. In some other
embodiments, the conductive pads 114a and the conductive pads 116a
may be formed by different materials and/or different processes
according to the design requirement.
[0012] The core layer 112 may further include embedded circuit
layers serving as an intermediate circuit layer electrically
connected to the top circuit layer 114 and the bottom circuit layer
116. The core layer 112 may include a base layer and a plurality of
conductive vias penetrating through the base layer. The two
opposite ends of the conductive vias of the core layer 112 may
electrically connect to the conductive pads 114a of the top circuit
layer 114 and the conductive pads 116a of the bottom circuit layer
116. In some embodiments, the first package structure 100 may
include a plurality of conductive structures 118 formed on the
bottom surface S2 of the first package structure 100. For example,
a material of the conductive structures 118 may include copper,
tin, gold, nickel or other suitable conductive material. The
conductive structures 118 may be, for example, conductive bumps,
conductive pillars, or solder balls formed by a ball placement
process and a reflow process. It should be noted that other
possible forms and shapes of the conductive structures 118 may be
utilized for further electrical connection. In some embodiments,
the conductive structures 118 may form an array arranged to have
fine pitch on the bottom surface S2 of the first circuit carrier
110 for requirement in the subsequent processes.
[0013] A first die 120 may be disposed on the top surface S1 of the
first circuit carrier 110. The first die 120 may be electrically
connected to the first circuit carrier 110 through flip-chip
bonding. In some embodiment, an active surface (not illustrated) of
the first die 120 is coupled to the conductive pads 114a of the top
circuit layer 114 of the first circuit carrier 110 through a
plurality of conductive bumps 122. The conductive bumps 122 may be
copper bumps. In some embodiments, solders (not illustrated) may be
applied onto surfaces of the conductive bumps 122 to couple with
the conductive pads 114a. The first die 120 may be, for example, an
ASIC (Application-Specific Integrated Circuit). In some
embodiments, the first die 120 may be used to perform logic
applications. However, it construes no limitation in the
disclosure. Other suitable active devices may also be utilized as
the first die 120.
[0014] Referring to FIG. 1B, a spacer 130 is disposed on the first
die 120. In addition, the spacer 130 is bonded to the first die 120
through an adhesive layer 140. In some embodiments, the adhesive
layer 140 may be a die attach film or forming from the adhesive
composition including an epoxy resin. The adhesive layer 140 may be
formed by methods such as spin coating, inject printing or other
suitable methods for providing a structural support without the
need for mechanical clamping between the first die 120 and the
spacer 130.
[0015] The spacer 130 may include a second circuit carrier 132 with
conductive pads on the surface opposite to the first die 120 for
the subsequent bonding process. It should be noted that other
suitable forms of the spacer 130 may be utilized and the details
will be described later in other embodiments. In some embodiments,
the spacer 130 may serve as a dummy chip for performing the
subsequent wire bonding process and/or providing a spacer function
to prevent damage to the first die 120. The size and the thickness
of the spacer 130 may construe no limitation to the unit sizes and
unit thicknesses of the first die 120. In some embodiment, the
spacer 130 may be a semiconductor carrier having a similar shape or
appearance as that of a chip while not having active devices formed
therein. In some other embodiments, the spacer 130 and the first
die 120 may be mechanically coupled but electrically isolated from
each other when the entire manufacturing process is completed.
[0016] Referring to FIG. 1C, the spacer 130 and the first circuit
carrier 110 are connected through a plurality of conductive wires
150. For example, the conductive wires 150 may be formed through a
wire bonder (not illustrated). The types of the wire bonder may
include wedge bond or ball bond or other suitable wire bonder
according to the design requirement. Moreover, the conductive wires
150 are connected between the second circuit carrier 132 of the
spacer 130 and the first circuit carrier 110. A material of the
conductive wires 150 may be gold, copper or other suitable
material, which is not limited thereto. In some embodiments, each
of the conductive wires 150 may include a first welding segment
152, a sacrificial segment 154 and a second welding segment 156.
Each of the first welding segments 152 of the conductive wires 150
is coupled to the first circuit carrier 110 and each of the second
welding segments 156 of the conductive wires 150 is coupled to the
second circuit carrier 132 of the spacer 130. The conductive wires
150 are formed from the first circuit carrier 110 to the spacer
130. Moreover, each of the sacrificial segments 154 of the
conductive wires 150 is formed between one of the first welding
segments 152 and one of the second welding segments 156. In other
word, each of the conductive wires 150 may be formed in the
sequence of the first welding segment 152, the sacrificial segment
154 and the second welding segment 156.
[0017] In some embodiments, the wire bonder may include an
automated device that welds the conductive wires 150. For instance,
each of the conductive wires 150 is fed through a bonding tool such
as a capillary (not illustrated) that applies heat, ultrasonic
energy, pressure, or the combination thereof to bond each of the
conductive wires 150 between the first circuit carrier 110 and the
spacer 130. In some embodiments, each of the first welding segments
152 of the conductive wires 150 may include a welding portion 152a
bonded to the first circuit carrier 110 and a wire portion 152b
coupled to the welding portion 152a. For example, the welding
portion 152a of each of the first welding segments 152 may be
formed through ball bond, wedge bond, or other suitable bond
depending on the design requirement. After bonding the welding
portion 152a to the top surface S1 of the first circuit carrier
110, the wire portion 152b of each of the first welding segments
152 coupled to the welding portion 152a may be delivered out by the
bonding tool of the wire bonder. For instance, the bonding tool of
the wire bonder may move upwards from the first circuit carrier 110
to form the wire portion 152b in a vertical manner.
[0018] Next, the bonding tool may move in a direction upward away
from the first circuit carrier 110 and towards the spacer 130 to
form the sacrificial segment 154. An arcing shape in the
sacrificial segment 154 of each of the conductive wires 150 may be
formed. In addition, a loop height H1 of each of the conductive
wires 150 may be a distance between the peak of the arcing shape of
the sacrificial segment 154 and the bottom end of the welding
portion 152a of the first welding segment 152 coupled to the first
circuit carrier 110. The loop height H1 may depend on the type of
the wire bonder and/or the design requirement, which is not limited
thereto. Subsequently, the bonding tool of the wire bonder may be
positioned at the conductive pads of the second circuit carrier 132
of the spacer 130 and a tail bond of each of the second welding
segment 156 of the conductive wires 150 may be formed to bond the
second circuit carrier 132. As such, the wire bonding process on,
the first circuit carrier 110 and the second circuit carrier 132 of
the spacer 130 is completed.
[0019] In some embodiments, an angle .theta.1 between the first
welding segment 152 of each of the conductive wires 150 and the
first circuit carrier 110 is greater than or equal to an angle
.theta.2 between the second welding segment 156 of each of the
conductive wires 150 and the spacer 130. The angle .theta.1 may
depend on the types of the wire bonding and/or the design
requirement. For example, a ball bonder welds a conductive ball on
the conductive pads 114a of the first circuit carrier 110 to a
contact with each of the conductive wire 150 extending away from
the conductive ball at right angle. However, for the wedge bonder,
in some embodiments, it presses the side of the conductive wires
150 against the contact so the angle .theta.1 between each of the
first welding segments 152 of the conductive wires 150 and the top
surface S1 of the first circuit carrier 110 may be less than 90
degree, but substantially close to 90 degree. In some other
embodiments, each of the second welding segments 156 of the
conductive wires 150 may be perpendicular to the spacer 130. As
such, the angle .theta.2 may be 90 degree or substantially close to
90 degree.
[0020] Referring to FIG. 1D, an encapsulant 160 is formed on the
top surface S1 of the first circuit carrier 110 to encapsulate the
first die 120, the spacer 130, the adhesive layer 140, and the
conductive wires 150. In some embodiments, a thickness T1 of the
encapsulant 160 is greater than the loop height H1 of each of the
conductive wires 150. The encapsulant 160 may include a molding
compound formed by a molding process. In some embodiments, the
encapsulant 160 may be formed by an insulating material such as
epoxy or other suitable resins. However, it construes no limitation
in the disclosure.
[0021] Referring to FIG. 1E, the thickness T1 of the encapsulant
160 is reduced until at least a portion of each of the conductive
wires 150 are removed to form a first package structure 100. For
instance, the thickness T1 of the encapsulant 160 is reduced to a
thickness T2 as shown in FIG. 1E. When the thickness T1 of the
encapsulant 160 is reduced, the sacrificial segments 154 of the
conductive wires 150 may be removed. In addition, a portion of each
of the first welding segments 152 of the conductive wires 150 and a
portion of each of the second welding segments 156 of the
conductive wires 150 may be exposed through the encapsulant 160. In
other word, since the sacrificial segments 154 of the conductive
wires 150 are removed while the portion of the first welding
segments 152 and the portion of the second welding segments 156
remain in the encapsulant 160, the conductive wires 150 is no
longer a continuous wires. Under this condition, the spacer 130 is
no longer coupled to the first circuit carrier 110 though the
conductive wires 150. As such, the spacer 130 is no longer
electrically connected to the first circuit carrier 110. In other
word, the spacer 130 serves as a dummy spacer after reducing the
thickness T1 of the encapsulant 160.
[0022] In some embodiments, the encapsulant 160 may be removed by a
grinding process. Moreover, the grinding process may be mechanical
grinding, chemical mechanical polishing (CMP), etching, or other
suitable method, which is not limited thereto. Moreover, after
reducing the thickness T1 of the encapsulant 160, a top surface of
the wire portion 152b of each of the first welding segment 152 and
a top surface of each of the second welding portion 156 are exposed
from the encapsulant 160. In some embodiments, after reducing the
thickness T1 of the encapsulant 160, the top surface of the wire
portion 152b of each of the first welding segment 152, the top
surface of each of the second welding portion 156, and a top
surface of the encapsulant 160 may be coplanar. Wherein, the top
surface of the encapsulant 160 may be the surface farthest from the
first circuit carrier 110. In other word, after reducing the
thickness T1 of the encapsulant 160, a height H2 of each of the
first welding segments 152 is equal to the thickness T2 of the
encapsulant 160.
[0023] In one embodiment, after reducing the thickness T1 of the
encapsulant 160, the top surface of the wire portion 152b may be
used for further electrical connection with the first circuit
carrier 110. The top surface of each of the second welding portion
156 may be dummy paths. In some other embodiments, after reducing
the thickness T1 of the encapsulant 160, both of the top surface of
the wire portion 152b of each of the first welding segment 152 and
the top surface of each of the second welding portion 156 may serve
as the conductive path for further electrical connection according
to the design requirement. In addition, it should be noted that the
thickness reducing process as shown in FIG. 1E is able to aid the
overall thickness reduction in the package structure as a whole,
thereby achieving package miniaturization.
[0024] Referring to FIG. 1F, a second package structure 200 is
stacked on the first package structure 100 to form a
package-on-package (POP) structure 10. For example, the second
package structure 200 is electrically connected to the conductive
wires 150 of the first package structure 100. In some embodiments,
the second package structure 200 may include a second die 202 such
as DRAM or NAND flash memory. In some other embodiments, other
active devices may also be utilized in the second package structure
200. In some embodiments, the second package structure 200 may
include a plurality of conductive terminals 204 as the electrical
connection path between the second package structure 200 and the
first package structure 100. Moreover, in some embodiments, the
second die 202 and the conductive terminals 204 may be electrically
connected through circuit layers similar to the connection between
the first die 120 and the conductive structures 118.
[0025] In one embodiment, the second package structure 200 may
include a central region CR and a peripheral region PR surrounding
the central region CR. For instance, the second die 202 may be
located in the central region CR and the conductive terminals 204
may be disposed in the peripheral region PR. Moreover, when the
second package structure 200 is stacked on the first package
structure 100, the second die 202 in the central region CR of the
second package structure 200 may be disposed corresponding to the
first die 120 of the first package structure 100. In addition, each
of the conductive terminals 204 in the peripheral region PR of the
second package structure 200 may be disposed on one of the first
welding segments 152 of the conductive wires 150 exposed by the
encapsulant 160 of the first package structure 100, respectively.
In one embodiment, the second die 202 in the central region CR of
the second package structure 200 may be staggered from the first
die 120 of the first package structure 100. In another embodiment,
the conductive terminals 204 may be disposed in both of the central
region CR and the peripheral region PR for electrical connection to
the first package structure 100. In some embodiments, a thermal
conductive layer (not illustrated) may be disposed in thermal
contact or thermally coupled between the second package structure
200 and the first package structure 100 for enhancing the heat
dissipation efficiency. As such, the stress applied onto the POP
structure 10 during the subsequent reliability tests may be shared
by the thermal conductive layer for increasing the reliability of
the POP structure 10.
[0026] Since the first welding segments 152 may serve as the
electrical connection path between the first package structure 100
and the second package structure 200, an additional interposer for
electrically connecting between the first package structure 100 and
the second package structure 200 can be omitted. Thereby the
overall thickness of the POP structure 10 and the manufacturing
costs may be reduced.
[0027] FIG. 2A to FIG. 2F are schematic cross-sectional views
illustrating manufacturing method of a POP structure according to
another embodiment of the disclosure. Referring to FIG. 2A, the
first circuit carrier 110 is provided and the first die 120 is
bonded on the first circuit carrier 110. It should be noted that
the embodiment of FIG. 2A is similar to the embodiment of FIG. 1A,
so the detailed descriptions are omitted herein.
[0028] Referring to FIG. 2B, a spacer 330 is disposed on the first
circuit carrier 110 and bonded to the first die 120. For example,
the spacer 330 includes a conductive plate 332 serving as a
heat-dissipating metal plate. In addition, the conductive plate 332
of the spacer 330 may be suitable for performing the subsequent
wire bonding process. A material of the conductive plate 332 may
include a thermally and electrically conductive material such as
aluminum, copper or alloys thereof. However, a material of the
conductive plate 332 depends on the design requirement construing
no limitation the disclosure.
[0029] Moreover, a thermal adhesive layer 340 may be disposed
between the first die 120 and the spacer 330. In some embodiments,
the thermal adhesive layer 340 may include die attach compositions
possessing a high thermal conductivity such as silver, silver
coated or aluminium nitride particles formed by such as spin
coating, inject printing or other suitable methods. However, a
material and forming processes of the thermal adhesive layer 340
construe no limitation in the disclosure. The thermal adhesive
layer 340 may serve as a direct thermal conductivity path from the
first die 120 to the spacer 330 and further enhance the heat
dissipation efficiency during the heat generated from the first die
120. Furthermore, the thermal adhesive layer 340 may provide a
structural support without the need for mechanical clamping between
the first die 120 and the spacer 330.
[0030] Referring to FIG. 2C, the spacer 330 and the first circuit
carrier 110 are connected through a plurality of conductive wires
350. It should be noted that a material and forming methods of the
conductive wires 350 may be similar to the material and the forming
methods of the conductive wires 150 shown in FIG. 1C. The detailed
descriptions are omitted herein. In the present embodiment, the
conductive wires 350 may be connected between the conductive plate
332 of the spacer 330 and the first circuit carrier 110. In
addition, each of the conductive wires 350 may include a welding
segment 352 connected to the first circuit carrier 110 and a
sacrificial segment 354 connected between the welding segment 352
and the spacer 330. In other word, the conductive wires 350 are
connected from the first circuit carrier 110 through the welding
segment 352 to the spacer 330 through the sacrificial segment
354.
[0031] In addition, each of the welding segments 352 of the
conductive wires 350 may include a welding portion 352a coupled to
the first circuit carrier 110 and a wire portion 352b connected to
the welding portion 352a. For example, the welding portion 352a of
each of the welding segments 352 may be formed through ball bond,
wedge bond or other suitable bond depending on the design
requirement. It should be noted that the forming process of the
welding portions 352a and the wire portions 352b of the welding
segments 352 may be similar to the forming process of the welding
portions 152a and the wire portions 152b of the first welding
segments 152 illustrated in FIG. 1C. The detailed descriptions are
omitted herein.
[0032] Each of the sacrificial segments 354 of the conductive wires
350 may include an arc-shape portion 354a and a tail portion 354b.
The forming process of the sacrificial segments 354 may be similar
to the forming process of the sacrificial segments 154 and the
second welding segments 156 of the conductive wires 150. The
detailed descriptions are omitted herein. In addition, a loop
height H3 of each of the conductive wires 350 may be a distance
between the peak of the arc-shape portion 354a of the sacrificial
segment 354 and the bottom end of the welding portion 352a of the
first welding segment 352 coupled to the first circuit carrier 110.
It should be noted that the loop height H3 depends on the types of
the wire bonder and/or the design requirement, which is not limited
thereto.
[0033] In some embodiments, an angle .theta.3 between the welding
segment 352 of each of the conductive wires 350 and the first
circuit carrier 110 is greater than an angle .theta.4 between the
sacrificial segment 354 of each of conductive wires 350 and the
spacer 330. Similar to the embodiment illustrated in FIG. 1C, in
the present embodiment, the angle .theta.3 (similar to the angle
.theta.1) and the angle .theta.4 (similar to the angle .theta.2)
may depend on the types of the wire bonding and/or the design
requirement.
[0034] Referring to FIG. 2D, the encapsulant 160 is formed on the
first circuit carrier 110 to encapsulate the first die 120, the
spacer 330, the adhesive layer 340 and the conductive wires 350. It
should be noted that the process of the embodiment illustrated in
FIG. 2D is similar to the process of the embodiment of illustrated
in FIG. 1D, so the detailed descriptions are omitted herein.
Referring to FIG. 2E, the thickness T1 of the encapsulant 160 is
reduced until at least a portion of each of the conductive wires
350 are removed to form a first package structure 300. The reducing
methods of the embodiment illustrated in FIG. 2E is similar to the
reducing methods of the embodiment of illustrated in FIG. 1E, so
the detailed descriptions are omitted herein.
[0035] In the present embodiment, the sacrificial segments 354 of
the conductive wires 350 are removed. For instance, the thickness
T1 of the encapsulant 160 is reduced to a thickness T3 as shown in
FIG. 2E. In addition, after reducing the thickness T1 of the
encapsulant 160, a top surface 332a of the conductive plate 332 of
the spacer 330 is exposed from the encapsulant 160. Moreover, a top
surface of the wire portion 352b of each of the welding segments
352 of the conductive wires 350 are exposed through the encapsulant
160. In other word, the sacrificial segments 354 of the conductive
wires 350 are removed while a portion of the welding segments 352
remain in the encapsulant 160. Under this condition, the spacer 330
is not connected to the conductive wires 350 and also no longer
electrically connected to the first circuit carrier 110 though the
conductive wires 350. As such, the spacer 330 is no longer
electrically connected to the first circuit carrier 110. In some
embodiments, after reducing the thickness T1 of the encapsulant
160, the top surface of the wire portion 352b of each of the
welding segment 352, the top surface 332a of the conductive plate
332 of the spacer 330 and a top surface of the encapsulant 160 are
coplanar. Wherein, the top surface of the encapsulant 160 may be
the surface farthest from the first circuit carrier 110. In other
word, after reducing the thickness T1 of the encapsulant 160, a
height H4 of each of the welding segments 352 is equal to the
thickness T3 of the encapsulant 160. In addition, it should be
noted that the thickness reducing process as shown in FIG. 2E is
able to aid the overall thickness reduction in the package
structure as a whole, thereby achieving package miniaturization.
Moreover, the spacer 330 including the conductive plate 332 may
first serve as the conductive bonding pad for forming the
conductive wires 350 as shown in FIG. 2D. Subsequently, since the
sacrificial segments 354 of the conductive wires 350 are removed
after reducing the thickness T1 of the encapsulant 160, the spacer
330 is electrically floated. Therefore, the spacer 330 including
the conductive plate 332 may be used as the heat-dissipating
element in the first package structure 300.
[0036] Referring to FIG. 2F, the second package structure 200 is
stacked on the first package structure 300 to form a POP structure
20. For example, the second package structure 200 is electrically
connected to the conductive wires 350 of the first package
structure 100. In some embodiments, when the second package
structure 200 is stacked on the first package structure 300, the
second die 202 in the central region CR of the second package
structure 200 may be disposed corresponding to the first die 120 of
the first package structure 300. In addition, each of the
conductive terminals 204 in the peripheral region PR of the second
package structure 200 may be disposed on one of the welding
segments 352 of the conductive wires 350 exposed by the encapsulant
160 of the first package structure 300. In one embodiment, the
second die 202 in the central region CR of the second package
structure 200 may be staggered from the first die 120 of the first
package structure 300. In another embodiment, the conductive
terminals 204 may be disposed in both of the central region CR and
the peripheral region PR of the second package structure 200 for
electrical connection to the first package structure 300.
[0037] Based on the above, the spacer disposed on the die is
conducive to the forming process of the conductive wires. Moreover,
since at least a portion of the conductive wires are removed during
reducing the thickness of the encapsulant, the rest portion of the
conductive wires remaining in the encapsulant may be used as the
electrical connecting path between the first package structure and
the second package structure. As a result, it is unnecessary to
dispose additional interposer between the first package structure
and the second package structure for electrical connection.
Therefore, not only the overall thickness of the POP structure but
the manufacturing cost may be reduced. In addition, the spacer may
be exposed from the encapsulant so the spacer may serve as a
heat-dissipating element after reducing the thickness of the
encapsulant. As such, it may open the possibility to various POP
structure designs.
[0038] It will be apparent to those skilled in the art that various
modifications and variations can be made to the structure of the
present disclosure without departing from the scope or spirit of
the disclosure. In view of the foregoing, it is intended that the
present disclosure cover modifications and variations of this
disclosure provided they fall within the scope of the following
claims and their equivalents.
* * * * *