U.S. patent application number 11/968873 was filed with the patent office on 2008-05-08 for stackable molded packages and methods of making the same.
This patent application is currently assigned to Freescale Semiconductor, Inc. Invention is credited to Marc A. Mangrum, Addi B. Mistry, David T. Patten, Jesse Phou, Ziep Tran.
Application Number | 20080108179 11/968873 |
Document ID | / |
Family ID | 38174159 |
Filed Date | 2008-05-08 |
United States Patent
Application |
20080108179 |
Kind Code |
A1 |
Mistry; Addi B. ; et
al. |
May 8, 2008 |
STACKABLE MOLDED PACKAGES AND METHODS OF MAKING THE SAME
Abstract
A first packaged integrated circuit (IC) includes a package
substrate, at least one IC die attached to a first surface of the
package substrate, a plurality of conductive members on the first
surface at least partially surrounding the at least one IC die and
electrically connected to the at least one IC die, an encapsulant
over the first surface surrounding the at least one IC die and the
plurality of conductive members, wherein at least a portion of each
of the plurality of conductive members is exposed by the
encapsulant. A second packaged IC may be stacked onto the first
packaged IC. The second packaged IC includes at least one IC die
and a plurality of conductive members, each conductive member of
the plurality of conductive members of the second packaged IC is in
contact with a corresponding conductive member of the plurality
conductive members of the first packaged IC.
Inventors: |
Mistry; Addi B.; (Austin,
TX) ; Mangrum; Marc A.; (Manchaca, TX) ;
Patten; David T.; (Austin, TX) ; Phou; Jesse;
(Austin, TX) ; Tran; Ziep; (Austin, TX) |
Correspondence
Address: |
FREESCALE SEMICONDUCTOR, INC.;LAW DEPARTMENT
7700 WEST PARMER LANE MD:TX32/PL02
AUSTIN
TX
78729
US
|
Assignee: |
Freescale Semiconductor,
Inc
Austin
TX
|
Family ID: |
38174159 |
Appl. No.: |
11/968873 |
Filed: |
January 3, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11311579 |
Dec 16, 2005 |
|
|
|
11968873 |
Jan 3, 2008 |
|
|
|
Current U.S.
Class: |
438/117 ;
257/E21.502; 257/E23.114; 257/E23.14; 257/E25.023; 438/127 |
Current CPC
Class: |
H01L 23/24 20130101;
H01L 2924/1532 20130101; H01L 2224/32225 20130101; H01L 2924/00012
20130101; H01L 2924/00012 20130101; H01L 23/552 20130101; H01L
2224/48091 20130101; H01L 24/97 20130101; H01L 2924/00014 20130101;
H01L 2924/00014 20130101; H01L 2224/97 20130101; H01L 2224/97
20130101; H01L 2924/00 20130101; H01L 24/48 20130101; H01L
2924/15311 20130101; H01L 2924/3511 20130101; H01L 21/561 20130101;
H01L 2924/00014 20130101; H01L 2224/97 20130101; H01L 2924/01029
20130101; H01L 2224/48227 20130101; H01L 2924/01033 20130101; H01L
2924/15331 20130101; H01L 25/105 20130101; H01L 2225/1023 20130101;
H01L 2224/97 20130101; H01L 2924/01015 20130101; H01L 2924/3025
20130101; H01L 2224/32225 20130101; H01L 2924/181 20130101; H01L
2224/97 20130101; H01L 2225/1058 20130101; H01L 23/3128 20130101;
H01L 2924/15311 20130101; H01L 2924/181 20130101; H01L 2924/01075
20130101; H01L 2224/73204 20130101; H01L 2924/14 20130101; H01L
2224/73265 20130101; H01L 2924/15311 20130101; H01L 2224/16225
20130101; H01L 2224/48091 20130101; H01L 2224/73204 20130101; H01L
2224/73265 20130101; H01L 24/73 20130101; H01L 2224/32225 20130101;
H01L 2224/32225 20130101; H01L 2224/73265 20130101; H01L 2224/73265
20130101; H01L 2224/48227 20130101; H01L 2924/207 20130101; H01L
2924/00014 20130101; H01L 2224/16225 20130101; H01L 2924/00
20130101; H01L 2224/73204 20130101; H01L 2224/32225 20130101; H01L
2224/85 20130101; H01L 2224/48227 20130101; H01L 2924/00012
20130101; H01L 2224/81 20130101; H01L 2224/16225 20130101; H01L
2924/00 20130101; H01L 2224/32225 20130101; H01L 2224/48227
20130101; H01L 2224/45015 20130101; H01L 2224/45099 20130101; H01L
2924/15311 20130101 |
Class at
Publication: |
438/117 ;
438/127; 257/E21.502 |
International
Class: |
H01L 21/56 20060101
H01L021/56 |
Claims
1. A method for forming a packaged integrated circuit (IC)
comprising: providing a package substrate having a first surface, a
first IC die attached to the first surface, a plurality of
conductive members on the first surface at least partially
surrounding the first IC die and electrically connected to the
first IC die, and a dam on the first surface at least partially
surrounding the plurality of conductive members; and performing a
surface fill by providing an encapsulant to the first surface of
the package substrate wherein the encapsulant surrounds the first
IC die and is at least partially contained by the dam and wherein
performing the surface fill further includes providing a protection
element in physical contact with a top portion of each of the
plurality of conductive members and removing the protection
element, such that the top portion of each of the plurality of
conductive members remains exposed after the protection element is
removed.
2. The method of claim 1, wherein the package substrate has a
second surface, opposite the first surface, the second surface
having a plurality of external conductive members.
3. The method of claim 1, wherein the package substrate has a
second IC die over the first surface.
4. The method of claim 3, wherein the second IC die is over the
first IC die.
5. The method of claim 1, wherein the first IC die is attached to
the first surface with a plurality of wirebonds.
6. The method of claim 1, wherein the first IC die is attached to
the first surface with a plurality of conductive bumps.
7. The method of claim 6, wherein providing the encapsulant to the
first surface comprises providing the encapsulant as an underfill
between the first IC die and the first surface.
8. The method of claim 1, wherein the dam completely surrounds the
plurality of conductive members together with the first IC die.
9. The method of claim 1, wherein the package substrate further
comprises a shielding support on the first surface for mounting a
shield.
10. The method of claim 9, wherein the shielding support is at
least one of a radio frequency shield or an electromagnetic
interference shield.
11.-24. (canceled)
25. The method of claim 1, wherein the protection element is a
protection plate that includes a plurality of indentations for
receiving each of the top portion of the plurality of conductive
members.
26. The method of claim 25, wherein providing the protection
element further comprises: providing a mold chase having the
protection plate therein over the package substrate, the protection
plate moveable inside the mold chase; and applying a force to bring
the protection plate into physical contact with the top portion of
each of the plurality of conductive members.
27. The method of claim 26, wherein the mold chase comprises a
spring between the mold chase and the protection plate to apply the
force.
28. The method of claim 1, wherein providing the protection element
further comprises providing a plurality of pad protectors into
physical contact with the plurality of conductive pads, wherein
each pad protector of the plurality of pad protectors is in
physical contact with a corresponding conductive pad of the
plurality of conductive pads.
29. The method of claim 28, wherein providing the plurality of pad
protectors comprises applying a vacuum through each of the
plurality of pad protectors.
30. The method of claim 28, wherein providing the plurality of pad
protectors comprises applying a force to maintain the plurality of
pad protectors in physical contact with the plurality of conductive
pads, and wherein during providing the encapsulant, applying at
least one of a positive pressure and a negative pressure through
each of the plurality of pad protectors.
31. A method for forming a packaged integrated circuit (IC)
comprising: providing a package substrate having a first surface, a
first IC die attached to the first surface, a plurality of
conductive members on the first surface at least partially
surrounding the first IC die and electrically connected to the
first IC die, and a dam on the first surface at least partially
surrounding the plurality of conductive members; and performing a
surface fill by providing an encapsulant to the first surface of
the package substrate wherein the encapsulant surrounds the first
IC die and is at least partially contained by the dam and wherein
performing the surface fill further includes providing a protection
element in physical contact with a top portion of each of the
plurality of conductive members, and removing the protection
element, such that the top portion of each of the plurality of
conductive members remains exposed after the protection element is
removed, wherein the protection element is selected from a group
consisting of a protection plate and a plurality of pad
protectors.
32. The method of claim 31, wherein the package substrate has a
second surface, opposite the first surface, the second surface
having a plurality of external conductive members.
33. The method of claim 31, wherein the package substrate has a
second IC die over the first surface.
34. The method of claim 33, wherein the second IC die is over the
first IC die.
35. The method of claim 31, wherein the first IC die is attached to
the first surface with a plurality of wirebonds.
36. The method of claim 31, wherein the first IC die is attached to
the first surface with a plurality of conductive bumps.
37. The method of claim 36, wherein providing the encapsulant to
the first surface comprises providing the encapsulant as an
underfill between the first IC die and the first surface.
38. The method of claim 31, wherein the dam completely surrounds
the plurality of conductive members together with the first IC
die.
39. The method of claim 31, wherein the package substrate further
comprises a shielding support on the first surface for mounting a
shield.
40. The method of claim 39, wherein the shielding support is at
least one of a radio frequency shield or an electromagnetic
interference shield.
Description
FIELD OF THE INVENTION
[0001] The present invention relates generally to integrated
circuit packages, and more particularly to stackable molded
packages and methods of making the same.
RELATED ART
[0002] Traditional stackable packages often warp resulting in poor
reliability of contacts with other packages. In general, such
stackable packages include a substrate and a molded die on top of
the substrate. Typically, the mold covering the die does not cover
the entire surface of the substrate. In such a stackable package,
the thin substrate, which is not supported by the mold in entirety,
is more prone to suffer from warpage. This warpage may result from
different thermal coefficients of expansion for the substrate and
the mold. Stackable packages may be stacked in a package-on-package
structure and may be interconnected using solder balls.
[0003] When conventional stackable packages are used in a
package-on-package structure, however, warpage of the stackable
package may result in poor contacts between stacked packages.
Conventionally, this problem has been addressed by increasing the
diameter and pitch of the solder balls interconnecting the stacked
packages. Increased diameter and pitch of the solder balls,
however, results in several problems. For example, use of larger
solder balls reduces the area available for the die and the metal
routing of the substrate. Furthermore, use of larger solder balls
increases the height of the package-on-package structure.
[0004] Thus, there is a need for improved stackable molded packages
and methods of making the same.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention is illustrated by way of example and
not limited by the accompanying figures, in which like references
indicate similar elements, and in which:
[0006] FIG. 1 is a top view of an exemplary substrate strip,
consistent with one embodiment of the invention;
[0007] FIG. 2 is a cross section view of the exemplary substrate
strip of FIG. 1 with wire-bonded dies, consistent with one
embodiment of the invention;
[0008] FIG. 3 is a cross section view of the exemplary substrate
strip of FIG. 2 with dams and conductive balls, consistent with one
embodiment of the invention;
[0009] FIG. 4 is a cross section view of the exemplary substrate
strip of FIG. 3 with the encapsulant dispensed between dams,
consistent with one embodiment of the invention;
[0010] FIG. 5 is a cross section view of an exemplary substrate
strip with a flip chip die, consistent with one embodiment of the
invention;
[0011] FIG. 6 is a top view of an exemplary top mold chase with
vacuum-assisted pad protectors, consistent with one embodiment of
the invention;
[0012] FIG. 7 is a cross section view of a substrate inside a mold
chase, consistent with one embodiment of the invention;
[0013] FIG. 8 is a cross section view of a substrate with mold
injected on top of the substrate, consistent with one embodiment of
the invention;
[0014] FIG. 9 is a cross section view of an exemplary stackable
package, consistent with one embodiment of the invention;
[0015] FIG. 10 is a top view of an exemplary top mold chase with a
conductive ball protection plate, consistent with one embodiment of
the invention;
[0016] FIG. 11 is a cross section view of a substrate inside a mold
chase, consistent with one embodiment of the invention;
[0017] FIG. 12 is a cross section view of a substrate with mold
injected on top of the substrate, consistent with one embodiment of
the invention;
[0018] FIG. 13 is a cross section view of another exemplary
stackable package, consistent with one embodiment of the
invention;
[0019] FIG. 14 is a cross section view of an exemplary
package-on-package structure, consistent with one embodiment of the
invention;
[0020] FIG. 15 is a cross section view of an exemplary stackable
package with a shield, consistent with one embodiment of the
invention; and
[0021] FIG. 16 is a cross section view of another exemplary
package-on-package structure, consistent with one embodiment of the
invention.
[0022] Skilled artisans appreciate that elements in the figures are
illustrated for simplicity and clarity and have not necessarily
been drawn to scale. For example, the dimensions of some of the
elements in the figures may be exaggerated relative to other
elements to help improve the understanding of the embodiments of
the present invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0023] In one aspect, an exemplary method for forming a stackable
package, such as a packaged integrated circuit is provided. The
exemplary method may include providing a package substrate having a
first surface, a first IC die attached to the first surface, a
plurality of conductive members on the first surface at least
partially surrounding the first IC die and electrically connected
to the first IC die, and a dam on the first surface at least
partially surrounding the plurality of conductive members. The
exemplary method may further include performing a surface fill by
providing an encapsulant to the first surface of the package
substrate wherein the encapsulant surrounds the first IC die and is
at least partially contained by the dam and wherein portions of
each of the plurality of conductive members remain exposed during
the surface fill.
[0024] In another aspect, another exemplary method for forming a
packaged integrated circuit is provided. The method may include
providing a package substrate having a first surface, a first IC
die attached to the first surface, a plurality of conductive
members on the first surface at least partially surrounding the
first IC die and electrically connected to the first IC die. The
method may further include providing a protection plate in physical
contact with a top portion of each of the plurality of conductive
members. The method may further include providing an encapsulant
onto the first surface of the package substrate, wherein the
encapsulant surrounds the first IC die and each of the plurality of
conductive members, and wherein the protection plate remains in
physical contact with the top portion of each of the plurality of
conductive members during the providing the encapsulant. The method
may further include removing the protection plate, wherein after
removing the protection plate, the top portion of each of the
plurality of conductive members remains exposed.
[0025] In yet another aspect, a packaged integrated circuit is
provided. The packaged integrated circuit may include a first
packaged IC having a package substrate, at least one IC die
attached to a first surface of the package substrate, a plurality
of conductive members on the first surface at least partially
surrounding the at least one IC die and electrically connected to
the at least one IC die, an encapsulant over the first surface
surrounding the at least one IC die and the plurality of conductive
members, wherein at least a portion of each of the plurality of
conductive members is exposed by the encapsulant. The packaged
integrated circuit may further include a second packaged IC stacked
onto the first packaged IC, the second packaged IC having at least
one IC die and a plurality of conductive members electrically
connected to the at least one IC die of the second packaged IC,
each conductive member of the plurality of conductive members of
the second packaged IC in contact with a corresponding conductive
member of the plurality of conductive members of the first packaged
IC.
[0026] FIG. 1 is a top view of an exemplary substrate strip,
consistent with one embodiment of the invention. As part of the
process of forming stackable packages a substrate strip 10 may be
formed, which may include multiple substrate units. Substrate strip
10 may include die attach areas 16, to which die could be attached
later. Substrate strip 10 may further include bond posts 18 for
wire bonding die. FIG. 1 shows bond posts 18 for wire bonding die,
die may be connected to substrate strip 10 using other techniques,
such as flip chip bonding. Substrate strip 10 may further include
contact pads 20 for connecting stackable packages. Although FIG. 1
shows two rows/columns of contact pads 20 additional or fewer
rows/columns may also be used.
[0027] Substrate strip 10 may further include dam bars 12 and 14.
Dam bars 12 and 14 may be used to stop the flow of an encapsulant
material beyond the periphery of the stackable package. Dam bars 12
and 14 may be formed by depositing solder balls on a copper strip.
Alternatively, dam bars 12 and 14 may be formed by depositing any
suitable dam bar material, including conductive or non-conductive
materials. Furthermore, additional bars, such as bars 13 and 15 may
be formed by depositing suitable dam bar material. Bars 13 and 15
may serve as a radio frequency shield for a die attached to die
attach areas 16. Additionally and/or alternatively, bars 13 and 15
may serve to shield the die from interference, such as
electromagnetic interference. Also, shown in FIG. 1 is the
direction 22 of saw-street along which substrate strip 10 may be
singulated. Although FIG. 1 refers to a substrate strip 10 having a
row of substrate of units, an array of substrate units with more
than one row of substrate units may also be used. Referring now to
FIG. 2, as part of the process of forming stackable packages, die
24 may be wire bonded to substrate strip 10 using bond posts 18 and
wires 19.
[0028] FIG. 3 is a cross section view of the exemplary substrate of
FIG. 2 with dams, shielding bars, and conductive balls, consistent
with one embodiment of the invention. As part of this step, dams
26, shielding supports 31, and conductive balls 30 may be formed by
reflowing conductive material. Dams 26 (which may be formed using
conductive balls), conductive balls 30, and shielding supports may
be preformed and may be attached to respective contact areas.
[0029] FIG. 4 is a cross section view of the exemplary substrate of
FIG. 3 with the encapsulant dispensed between dams, consistent with
one embodiment of the invention. As shown, as the next step of
forming stackable packages, an encapsulant 34 may be dispensed on
the top surface of substrate strip 10 using dispensers 32, for
example. Dams 26 may prevent the flow of encapsulant 34 beyond the
periphery of the stackable packages. Any conventional encapsulants
may be used as part of this step. External conductive balls 36 may
be formed on a bottom surface of substrate strip 10. Alternatively,
preformed external conductive balls 36 may be attached to the
bottom surface of substrate strip 10. Referring to FIG. 5, flip
chip die 38 may also be used as part of stackable packages.
Encapsulant 34 may act as an underfill between flip chip die 38 and
a top surface of substrate strip 10. As part of the final step,
stackable packages may be singulated. Die may be attached to
substrate strip 10 using processes other than wire bonding and flip
chip bonding.
[0030] Consistent with another embodiment of the invention,
stackable packages may also be formed using a molding process. FIG.
6 is a top view of an exemplary top mold chase with vacuum-assisted
pad protectors, consistent with one embodiment of the invention,
which may be used as part of the molding process. Top mold chase 50
may include vacuum-assisted pad protectors 52 located in vacuum
housing 51. Vacuum housing 51 may be of the same material as the
material of top mold chase 50. In addition, although not shown in
FIG. 7, inserts could be added to vacuum-assisted pad protectors 52
or to vacuum housing 51 in order to, for example, narrow the area
covered by vacuum-assisted pad protectors 52 resulting in a
variable pad width. Top mold chase 50 may further include a vacuum
tube 54. Using vacuum tube 54, the interface between
vacuum-assisted pad protectors 52 and contact pads 66 may be made
substantially air-tight and thus preventing flow of any molding
material into an area above contact pads 66. Top mold chase 50 may
further include a mold injecting tube 56. Molding material may be
injected using mold injecting tube 56. Referring to FIG. 7 now, a
cross section view of a substrate inside a mold chase is shown.
Substrate 60, including a die 62 attached to it, may be held
between top mold chase 50 and bottom mold chase 58. Molding
material 64 (shown in FIG. 8) may be injected using mold injecting
tube 56. Vacuum tube 54 may be used to prevent the molding material
from flowing into an area above contact pads 66. By way of another
example, instead of applying vacuum through vacuum-assisted pad
protectors 52, a positive pressure may be applied through
vacuum-assisted pad protectors 52 to prevent the molding material
from flowing into an area above contact pads 66. The application of
positive pressure and/or vacuum could be controlled during the
molding process to prevent overflow on the contact pads 66.
Referring further to FIG. 8, molding material 64 is shown as
filling the area between top mold chase 50 and substrate 60, except
the area occupied by die 62 and the area protected by
vacuum-assisted pad protectors 52.
[0031] FIG. 9 is a cross section view of an exemplary stackable
package, consistent with one embodiment of the invention. Stackable
package may include die 62 attached to substrate 60 with molding
material 64 on top. Stackable package may further include
conductive material 68 filled into the area protected by
vacuum-assisted pad protectors 52. Conductive material 68 may be
filled using conventional processes and then leveled using a solder
squeegee, for example. Conductive material 68 may be reflowed and
the stackable package grinded, if necessary. Solder balls may also
be inserted in the area above contact pads 66, which could then be
reflowed to form conductive material 68. Additionally, external
conductive balls 63 may be formed on a bottom surface of substrate
60 for connecting the stackable package to other packages or other
components, such as printed circuit boards. Although FIG. 9 shows
die 62 as being wire bonded to substrate 60, die 62 may be attached
to substrate 60 using other techniques, such as flip chip bonding.
Further, stackable packages may be formed using other exemplary
mold processes, as well. For example, as described below, a mold
chase with a conductive ball protection plate may also be used to
form stackable packages.
[0032] As shown in FIG. 10, a top mold chase 70 may include a
conductive ball protection plate 72. Top mold chase 70 may further
include a mold injection tube 76. Referring now to FIG. 11, a cross
section view of a substrate 80 inside a mold chase is shown.
Substrate 80, including a die 82 attached to it, may be held
between top mold chase 70 and bottom mold chase 78. Molding
material 86 (shown in FIG. 12) may be injected using mold injecting
tube 76. Alignment indentations 73 formed in conductive ball
protection plate 72 may cover the top portion of conductive balls
74 to prevent the flow of molding material 86 on top of conductive
balls 74. Thus, after conductive ball protection plate 72 is
removed subsequent to the injection of molding material, a top
portion of conductive balls 74 may remain exposed. By way of
example, conductive ball protection plate 72 may be connected to
top molding plate 70 using springs 77. Springs 77 may provide
pressure to conductive ball protection plate 72 to ensure that
conductive ball protection plate 72 is not pushed up by molding
material 86. Referring further to FIG. 12, molding material 86 is
shown as filling the area between conductive ball protection plate
72 and substrate 80, except the area occupied by die 82. Molding
material 86 is also shown as an underfill for die 82.
[0033] FIG. 13 is a cross section view of an exemplary stackable
package, consistent with one embodiment of the invention. Stackable
package may include die 82 attached to substrate 80 with molding
material 86 on top. Stackable package may further include
conductive balls 74, whose top portion is not covered by molding
material 86 and is thus exposed. Additionally, external conductive
balls 88 may be formed on a bottom surface of substrate 80 for
connecting the stackable package to other packages or other
components, such as printed circuit boards. Although FIG. 13 shows
die 82 as being flip chip bonded to substrate 80, die 82 may be
attached to substrate 80 using other techniques, such as wire
bonding.
[0034] FIG. 14 is a cross section view of an exemplary
package-on-package structure 100, consistent with one embodiment of
the invention. In general, a package-on-package (POP) structure 100
may be formed by stacking multiple packages. By way of example, POP
structure 100 may include a top package 90 over another stackable
package. Package 90 may include die 92 and die 94 encapsulated in
an encapsulant 98. Package 90 may further include connecting pads
96 for connecting package 90 to another package. Thus, as shown in
FIG. 14, conductive balls 74 may be connected to connecting pads 96
to connect package 90 to another stackable package. Any stackable
package described above may be used as part of POP structure 100.
Although FIG. 14 shows a non-stackable package stacked on top of a
stackable package, a stackable package may also be stacked on top
of the stackable package. Furthermore, any number of packages
and/or stackable packages may be stacked on top of each other. Each
package and/or stackable package may include one or more die.
External conductive balls 88 may be formed on a bottom or top
surface of any package, as and when necessary.
[0035] FIG. 15 is a cross section view of another exemplary
stackable package, consistent with one embodiment of the invention.
Stackable package may include die 82 attached to substrate 80 with
molding material 86 on top. Stackable package may further include
conductive balls 74, whose top portion is not covered by molding
material 86 and is thus exposed. Additionally, external conductive
balls 88 may be formed on a bottom surface of substrate 80 for
connecting the stackable package to other packages or other
components, such as printed circuit boards. Although FIG. 15 shows
die 82 as being flip chip bonded to substrate 80, die 82 may be
attached to substrate 80 using other techniques, such as wire
bonding. Stackable package may further include contact pads 85 with
shielding support, such as contact balls 87 connected to contact
pads 85. Additionally, a shield, such as a radio frequency shield
or an electromagnetic interference shield may be mounted on top of
shielding support/contact balls 87. Although FIG. 15 shows contact
balls 87 as shielding support, other types of shielding support may
also be used.
[0036] FIG. 16 is a cross section view of another exemplary
package-on-package structure 200, consistent with one embodiment of
the invention. In general, a package-on-package (POP) structure 200
may be formed by stacking multiple packages. By way of example, POP
structure 200 may include a top package 90 over another stackable
package. Package 90 may include die 92 and die 94 encapsulated in
an encapsulant 98. Package 90 may further include connecting pads
96 for connecting package 90 to another package. Thus, as shown in
FIG. 16, conductive balls 74 may be connected to connecting pads 96
to connect package 90 to another stackable package. Any stackable
package described above may be used as part of POP structure 200.
Although FIG. 16 shows a non-stackable package stacked on top of a
stackable package, a stackable package may also be stacked on top
of the stackable package. Furthermore, any number of packages
and/or stackable packages may be stacked on top of each other. Each
package and/or stackable package may include one or more die.
External conductive balls 88 may be formed on a bottom or top
surface of any package, as and when necessary. In addition,
package-on-package structure 200 may include a shield 91, which may
act as a radio frequency shield or an electromagnetic interference
shield. By way of example, contact pads 93 on a top surface of
bottom package may be formed, which may then have a shielding
support, such as contact balls 95 mounted thereon. Shield 91 may
then be attached to contact balls 95. Although FIG. 16 shows
contact balls 95 as shielding support, other types of shielding
support may also be used. Contact balls 87 and 95, acting as
shielding support, may be electrically connected through the
substrate to balls 88 which can be grounded to the desired
locations.
[0037] In the foregoing specification, the invention has been
described with reference to specific embodiments. However, one of
ordinary skill in the art appreciates that various modifications
and changes can be made without departing from the scope of the
present invention as set forth in the claims below. Accordingly,
the specification and figures are to be regarded in an illustrative
rather than a restrictive sense, and all such modifications are
intended to be included within the scope of present invention.
[0038] Benefits, other advantages, and solutions to problems have
been described above with regard to specific embodiments. However,
the benefits, advantages, solutions to problems, and any element(s)
that may cause any benefit, advantage, or solution to occur or
become more pronounced are not to be construed as a critical,
required, or essential feature or element of any or all the claims.
As used herein, the terms "comprises," "comprising," or any other
variation thereof, are intended to cover a non-exclusive inclusion,
such that a process, method, article, or apparatus that comprises a
list of elements does not include only those elements but may
include other elements not expressly listed or inherent to such
process, method, article, or apparatus.
* * * * *