U.S. patent application number 13/828430 was filed with the patent office on 2014-09-18 for package device including an opening in a flexible substrate and methods of forming the same.
The applicant listed for this patent is Taiwan Semiconductor Manufacturing Company, Ltd.. Invention is credited to Sao-Ling Chiu, Shang-Yun Hou, Cheng-Chieh Hsieh, Tsung-Shu Lin, Hung-An Teng.
Application Number | 20140264803 13/828430 |
Document ID | / |
Family ID | 51493362 |
Filed Date | 2014-09-18 |
United States Patent
Application |
20140264803 |
Kind Code |
A1 |
Lin; Tsung-Shu ; et
al. |
September 18, 2014 |
PACKAGE DEVICE INCLUDING AN OPENING IN A FLEXIBLE SUBSTRATE AND
METHODS OF FORMING THE SAME
Abstract
Methods and apparatus are disclosed for forming ultra-thin
packages for semiconductor devices on flexible substrates. A
flexible substrate may comprise a plurality of insulating layers
and redistribution layers. Openings of the flexible substrate may
be formed at one side of the flexible substrate, two sides of the
flexible substrate, or simply cut through the flexible substrate to
divide the flexible substrate into two parts. Connectors may be
placed within the opening of the flexible substrate and connected
to redistribution layers of the flexible substrate. Dies can be
attached to the connectors and electrically connected to the
connectors and to the redistribution layers of the flexible
substrate. Structure supports may be placed at another side of the
flexible substrate on the surface or within an opening.
Inventors: |
Lin; Tsung-Shu; (New Taipei
City, TW) ; Hsieh; Cheng-Chieh; (Yongkang District,
TW) ; Teng; Hung-An; (Taoyuan City, TW) ;
Chiu; Sao-Ling; (Hsin-Chu, TW) ; Hou; Shang-Yun;
(Jubei City, TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Taiwan Semiconductor Manufacturing Company, Ltd. |
Hsin-Chu |
|
TW |
|
|
Family ID: |
51493362 |
Appl. No.: |
13/828430 |
Filed: |
March 14, 2013 |
Current U.S.
Class: |
257/676 ;
438/123 |
Current CPC
Class: |
H01L 23/4985 20130101;
H01L 2224/73204 20130101; H01L 21/563 20130101; H01L 23/13
20130101; H01L 21/4857 20130101 |
Class at
Publication: |
257/676 ;
438/123 |
International
Class: |
H01L 23/498 20060101
H01L023/498; H01L 21/48 20060101 H01L021/48 |
Claims
1. A package device, comprising: a flexible substrate, wherein the
flexible substrate comprises a first insulating layer, a first
redistribution layer on the first insulating layer at a first side,
a second insulating layer on the first redistribution layer; a
first opening of the flexible substrate through the second
insulating layer and separating the second insulating layer into a
first portion and a second portion; one or more connectors placed
within the first opening of the flexible substrate and in contact
with the first redistribution layer; and a die on the one or more
connectors and electrically connected to the one or more
connectors.
2. The device of claim 1, further comprising an underfill material
filling the first opening of the flexible substrate.
3. The device of claim 1, further comprising a structure support
connected to the first insulating layer at a second side opposite
to the first side of the first insulating layer.
4. The device of claim 3, wherein the structure support is of a
material selected from the group consisting essentially of a
graphite, a material containing continuous carbon fiber, or a
metallic material.
5. The device of claim 1, wherein the die is connected to the one
or more connectors by a die redistribution layer.
6. The device of claim 1, wherein the first insulating layer has a
first height, the second insulating layer has a second height, a
ratio of the first height and the second height is in a range from
about 0.6 to about 1.
7. The device of claim 1, wherein the flexible substrate further
comprises: a second redistribution layer on the second insulating
layer; and a third insulating layer on the second redistribution
layer, wherein the first opening of the flexible substrate is
through the third insulating layer, the second redistribution
layer, and the second insulating layer.
8. The device of claim 1, wherein the flexible substrate further
comprises: a second redistribution layer next to the first
insulating layer at a second side opposite to the first side of the
first insulating layer; a third insulating layer next to the second
redistribution layer, wherein the first opening of the flexible
substrate through the second insulating layer at the first side of
the first insulating layer; and a second opening of the flexible
substrate through the third insulating layer and the second
redistribution layer.
9. The device of claim 8, further comprising a structure support
connected to the first insulating layer at the second side opposite
to the first side of the first insulating layer, within the second
opening of the flexible substrate.
10. The device of claim 1, wherein the first opening of the
flexible substrate extends through the first insulating layer and
the first redistribution layer to separate the flexible substrate
into a first part and a second part, a first connector of the one
or more connectors is on the first redistribution layer at the
first part of the flexible substrate, a second connector of the one
or more connectors is on the first redistribution layer at the
second part of the flexible substrate, and the die is on the first
connector and the second connector and electrically connected to
the first connector and the second connector.
11. The device of claim 10, further comprising a first structure
support connected to the first insulating layer at a second side
opposite to the first side of the first insulating layer at the
first part of the flexible substrate, and a second structure
support connected to the first insulating layer at the second side
opposite to the first side of the first insulating layer at the
second part of the flexible substrate.
12. A method for forming a package device comprising: forming a
first opening in a flexible substrate, wherein the flexible
substrate comprises a first insulating layer, a first
redistribution layer on the first insulating layer at a first side,
and a second insulating layer on the first redistribution layer,
and the first opening is through the second insulating layer;
placing a connector within the first opening of the flexible
substrate and in contact with the first redistribution layer; and
placing a die on the connector and electrically connected to the
connector.
13. The method of claim 12, further comprising filling the first
opening of the flexible substrate with an underfill material.
14. The method of claim 13, further comprising forming a structure
support connected to the first insulating layer at a second side
opposite to the first side of the first insulating layer.
15. The method of claim 12, wherein the forming the first opening
of the flexible substrate comprises forming the first opening
through the second insulating layer, the first insulating layer,
and the first redistribution layer, to separate the flexible
substrate into a first part, and a second part.
16. The method of claim 15, wherein the placing the connector
within the first opening of the flexible substrate comprises:
placing a first connector on the first redistribution layer at the
first part of the flexible substrate, placing a second connector on
the first redistribution layer at the second part of the flexible
substrate; and placing the die on the connector comprises: placing
the die on the first connector and on the second connector, and
electrically connected to the first connector and the second
connector.
17. The method of claim 12, wherein the forming the first opening
in the flexible substrate further comprises forming the first
opening through the second insulating layer, a third insulating
layer, and a second redistribution layer, wherein the flexible
substrate comprises the second redistribution layer on the second
insulating layer, and the third insulating layer on the second
redistribution layer.
18. A package device, comprising: a flexible substrate, wherein the
flexible substrate comprises a first insulating layer, a first
redistribution layer on the first insulating layer at a first side,
a second insulating layer on the first redistribution layer, and a
first opening of the flexible substrate through the second
insulating layer; a connector within the first opening of the
flexible substrate and in contact with the first redistribution
layer; a die on the connector and electrically connected to the
connector; and a structure support connected to the first
insulating layer at a second side opposite to the first side of the
first insulating layer.
19. The device of claim 18, wherein the flexible substrate further
comprises a second redistribution layer on the second insulating
layer, a third insulating layer on the second redistribution layer,
and the first opening of the flexible substrate is through the
third insulating layer, the second redistribution layer, and the
second insulating layer.
20. The device of claim 18, wherein the flexible substrate further
comprises a second redistribution layer next to the first
insulating layer at a second side opposite to the first side of the
first insulating layer, a third insulating layer next to the second
redistribution layer, the first opening of the flexible substrate
through the second insulating layer at the first side of the first
insulating layer, and a second opening of the flexible substrate
through the third insulating layer and the second redistribution
layer.
Description
BACKGROUND
[0001] Semiconductor devices are used in a variety of applications,
such as personal computers, cell phones, digital cameras, and many
other portable electronic equipment. These portable electronic
equipments need to be small, lightweight, and produced in high
volumes at relatively low cost.
[0002] Semiconductor devices such as portable electronic equipments
can be divided into a simple hierarchy consisting of devices such
as integrated circuit (IC) dies, packages, printed circuit boards
(PCB), and systems. The package is the interface between an IC die
and a PCB. IC dies are made from semiconductor materials such as
silicon. Dies are then assembled into a package. The packaged die
is then attached either directly to a PCB or to another substrate,
which may be a second level packaging. With the increasing demand
for portable electronic equipments, there is a need for the
development of smaller Integrated circuit (IC) packages with
reduced footprint and height.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] For a more complete understanding of the present disclosure,
and the advantages thereof, reference is now made to the following
descriptions taken in conjunction with the accompanying drawings,
in which:
[0004] FIGS. 1A-1E illustrate in cross-sectional views and a top
view a process of forming a package on a three layer flexible
substrate, in accordance with some embodiments;
[0005] FIGS. 2A-2D illustrate in cross-sectional views a process of
forming a package on a five layer flexible substrate, in accordance
with some embodiments;
[0006] FIGS. 3A-3B illustrate in cross-sectional views a process of
forming a package on a five layer flexible substrate with openings
on both sides, in accordance with some additional embodiments;
and
[0007] FIGS. 4A-4C illustrate in cross-sectional views a process of
forming a package on a five layer flexible substrate separated into
two components, in accordance with some additional embodiments.
[0008] Corresponding numerals and symbols in the different figures
generally refer to corresponding parts unless otherwise indicated.
The figures are drawn to clearly illustrate the relevant aspects of
the preferred embodiments and are not necessarily drawn to
scale.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0009] The making and using of the embodiments of the present
disclosure are discussed in detail below. It should be appreciated,
however, that the embodiments of the present disclosure provide
many applicable concepts that can be embodied in a wide variety of
specific contexts. The specific embodiments discussed are merely
illustrative of specific ways to make and use the disclosure, and
do not limit the scope of the disclosure.
[0010] Packages formed using flexible materials are revolutionizing
the packaging industry. Current flexible packages for portable
electronic equipments may suffer from shrinkage of the flexible
substrate of the package and the printed circuit boards (PCB) after
dies have been attached. The shrinkage of the flexible substrate
and the PCB leads to unstable dies and substrate warpage
problems.
[0011] With reference to FIG. 1A, a flexible substrate 1010 may be
provided. The flexible substrate 1010 may be used with the broadest
meaning and may not be limited to a flexible substrate for a
specific semiconductor package such as a chip on film (COF)
package. Rather, the flexible substrate 1010 may be used in a COF
package, a wafer level package (WLP), a ball grid array (BGA)
package, or any other package. The flexible substrate 1010 may be
used in flexible electronics, to meet the needs of flexible
applications, such as wearable electronics and flexible displays.
The targeted height for a package using the flexible substrate 1010
may be less than 200 um. The flexible substrate 1010 may not
normally include the PCB. The flexible substrate 1010 may comprise
a first insulating layer 1013, a first redistribution layer (RDL)
1015, and a second insulating layer 1017, as demonstrated in the
embodiments shown in the present disclosure.
[0012] The first insulating layer 1013 may provide the primary
physical and electrical properties of the flexible substrate. The
first insulating layer 1013 may be made from polyimide (PI),
polyester, polyethylene naphthalate (PEN), teflon, polyethylene
terephthalate (PET), or other polymeric materials. The material for
the first insulating layer 1013, such as the polyimide, may be
formed by spin-coating, followed by curing. The first insulating
layer 1013 may be of a first height H.sub.1 in a range from about
15 .mu.m to about 20 .mu.m.
[0013] The flexible substrate 1010 further comprises a first RDL
1015 formed on the first insulating layer 1013 at a first side.
While illustrated as a single layer in FIG. 1A, the first RDL 1015
comprises a plurality of conductive features isolated from each
other by dielectric material in order to form various conductive
connections to the connectors 1050 (described further below with
respect to FIGS. 1C-1D) and route signals to and from the
connectors 1050 around the flexible substrate 1010. As such, in an
embodiment, the first RDL 1015 may be formed by initially placing a
dielectric material and then performing, e.g., a damascene or dual
damascene process to inlay conductive material such as copper using
an electroplating process in a desired pattern for the first RDL
1015. Alternatively, in embodiments in which aluminum or other
conductive materials (e.g., metallic alloys) are utilized, the
conductive regions may be formed using a deposition process such as
sputtering followed by a masking and etching process, which may
then be covered by the dielectric material. Any suitable process
for forming the first RDL 1015 may alternatively be utilized. The
first RDL 1015 may have a second height H.sub.2 in a range from
about 20 .mu.m to about 24 .mu.m.
[0014] The flexible substrate 1010 further comprises a second
insulating layer 1017 formed above the first RDL 1015. The second
insulating layer 1017 may be made from polyimide (PI), polyester,
polyethylene naphthalate (PEN), teflon, polyethylene terephthalate
(PET), or other polymeric materials. The second insulating layer
1017 may be made of a same material or of a different material for
the first insulating layer 1013. The second insulating layer 1017
may be of a third height H.sub.3 in a range from about 30 .mu.m to
about 40 .mu.m. The height of the first insulating layer 1013 and
the height of the second insulating layer 1017 may be
different.
[0015] The total height of the first RDL 1015 and the first
insulating layer 1013 may be in a range from about 40 .mu.m to
about 44 .mu.m. The first height H.sub.1 of the first insulating
layer 103 and the second height H.sub.2 of the first RDL 1015 may
have a ratio in a range from about 0.6 to about 1. The first height
H.sub.1 of the first insulating layer 103 and the third height
H.sub.3 of the second insulating layer 107 may have a ratio in a
range from about 0.3 to about 0.7. The second height H.sub.2 and
the third height H.sub.3 may have a ratio in a range from about 0.5
to about 0.8. All the numbers are for examples only and are not
limiting. With the continuous reduction in feature sizes for
semiconductor devices, it is possible the first insulating layer
1013, the first RDL 1015, and the second insulating layer 1017 may
have smaller heights than described above.
[0016] As illustrated in FIG. 1B, a first opening 1012 may be
formed at the first side of the first insulating layer 1013,
through the second insulating layer 1017. The first opening 1012
exposes the first RDL 1015 so that a die 1030, not illustrated in
FIG. 1B but illustrated and discussed below in FIGS. 1C and 1D, may
be connected to the first RDL 1015. The first opening 1012 may be
formed around the middle of the flexible substrate 1010 so that a
first portion 1014 and a second portion 1016 of the second
insulating layer 1017 are separated by the first opening 1012 (a
top-down view of which is illustrated and discussed below with
respect to FIG. 1E), and so that the first portion 1014 and the
second portion 1016 are of a substantially similar length. The
length of the first opening 1012 may be slightly larger than a
length of the die 1030 which is going to be placed within the first
opening 1012.
[0017] The first opening 1012 may be formed using, e.g.,
photolithography techniques. In an embodiment, a photoresist
material (not shown) may be deposited above the second insulating
layer 1017. The photoresist material is then exposed through a mask
and developed to produce a pattern, so that the photoresist
material is removed in the area for the first opening 1012 to be
formed. The second insulating layer 1017 and the first RDL 1015 are
then removed in the first opening 1012 by etching, using the
patterned photoresist material as a mask.
[0018] As illustrated in FIGS. 1C and 1D, the die 1030 may be
placed on the flexible substrate 1010 to form a package 1000. The
package 1000 comprises, in addition to the flexible substrate 1010,
a connector 1050 or a plurality of connectors 1050 placed on and in
contact with the first RDL 1015, within the first opening 1012 (not
illustrated in FIG. 1C) of the flexible substrate 1010. The die
1030 is placed on the connectors 1050 and electrically connected to
the connectors 1050. The package 1000 further comprises an
underfill 1020 filling the first opening 1012 of the flexible
substrate 1010, covering the connectors 1050 and the first RDL
1015. The underfill 1020 may further extend over a surface of the
first portion 1014 and the second portion 1016 of the second
insulating layer 1017, covering a part of the surfaces of the first
portion 1014 and the second portion 1016 of the second insulating
layer 1017. The package 1000 may further comprise a structure
support 1070 connected to the first insulating layer 1013 at a
second side opposite to the first side of the first insulating
layer 1013.
[0019] The connectors 1050 may provide connections between the die
1030 and the first RDL 1015. The connectors 1050 may be contact
bumps such as micro-bumps or controlled collapse chip connection
(C4) bumps and may comprise a material such as tin, or other
suitable materials, such as silver or copper. In an embodiment in
which the connectors 1050 are tin solder balls, the connectors 1050
may be formed by initially forming a layer of tin through any
suitable method such as evaporation, electroplating, printing,
solder transfer, ball placement, etc. Once a layer of tin has been
formed on the structure, a reflow may be performed in order to
shape the material into the desired ball shape. The connectors 1050
may be of different sizes and shapes. As an example, the connectors
1050 shown in FIG. 1C may be solder balls placed on the first RDL
1015.
[0020] As another example, the connectors 1050 shown in FIG. 1D may
be metal pillars or solder joints directly formed on the first RDL
1015. The metal pillars may comprise solder pillar, copper, or
their alloys. The connectors 1050 may be of various shapes such as
a square, or a ball. The diameter of the connector 1050 when the
connector 1050 is of a ball shape, or the length of the connector
1050 when the connector 1050 is of a square shape, may be in a
range of about 50 .mu.m to about 100 .mu.m.
[0021] The die 1030 is placed on the connectors 1050. The die 1030
may be an integrated circuit chip formed from a semiconductor
wafer. The die 1030 may be any suitable integrated circuit die for
a particular application. For example, the die 1030 may be a memory
chip, such as a DRAM, SRAM, or NVRAM, or a logic circuit. The die
1030 may further comprise active devices, passive devices,
passivation layers, insulating layers, under bump metallization
(UBM) pads, which are not shown.
[0022] In an embodiment, the die 1030 may comprise a die RDL 1110,
in contact with the connectors 1050 to connect the die 1030 to the
first RDL 1015. The die RDL 1110 may be made with, e.g., Ti, Al,
Ni, nickel vanadium (NiV), Cu, or a Cu alloy. The formation methods
include electrolytic plating, electroless plating, sputtering, and
the like. The die RDL 1110 can be made with a single layer, or
multiple layers using an adhesion layer of Ti, TiW, or Cr, for
example. The die RDL 1110 may have a height between about 2 .mu.m
and about 10 .mu.m, for example, although the height of the die RDL
1110 is only shown for illustrative purposes and not limiting.
[0023] The underfill 1020 is placed between the die 1030 and the
surface of the first RDL 1015, filling the first opening 1012,
strengthening the attachment of the die 1030 to the flexible
substrate 1010, and preventing the thermal stresses from breaking
the connections between the die 1030 and the flexible substrate
1010. Generally, the material for the underfill 1020, such as
organic resin, is selected to control the coefficient of thermal
expansion and the shrinkage of underfill 1020. Initially, liquid
organic resin is applied that flows into the gap between the die
1030 and the surface of the first RDL 1015, which subsequently
cures to control the shrinkage that occurs in the underfill 1020
during curing.
[0024] The structure support 1070, also known as a stiffener, is
connected to the first insulating layer 1013 at a second side
opposite to the first side of the first insulating layer 1013. The
structure support 1070 may be a flat structure having substantially
a same size as a size of the die 1030, or having a bigger size than
the size of the die 1030. For example, the structure support 1070
may have a bigger size than the size of the die 1030, and may have
a length L in a range from about 50 .mu.m to about 150 .mu.m, and a
fourth height H.sub.4 in a range from about 20 .mu.m to about 100
.mu.m, although any suitable dimensions may alternatively be used.
As such, the structure support 1070 may have a ratio to the first
height H.sub.1 or between about 1 and about 6.7, a ratio to the
second height H.sub.2 of between about 0.8 to about 5, a ratio to
the third height H.sub.3 of between about 0.5 and about 3.3.
[0025] The structure support 1070 is used to constrain the flexible
substrate 1010 in order to prevent its warpage or other movement
relative to the die 1030, which may be caused by thermal cycling
(e.g., changes in temperature) during package assembly. Such
movement may result from the different coefficients of thermal
expansion of the die 1030 and the flexible substrate 1010
materials, and may produce stress in the die 1030 or the package in
causing electrical and mechanical failures. A suitable structure
support material may include graphite, such as natural graphite,
although any suitable structure support material may be used. For
example, materials containing continuous carbon fibers may be used.
The structure support material may further include a metallic
material. For example, copper, aluminum, or a ceramic may be
used.
[0026] The structure support 1070 is connected to the first
insulating layer 1013 by the adhesion layer 1071. In an embodiment
the structure support 1070 is connected to the first insulating
layer 1013 by an adhesion layer 1071. The adhesion layer 1071 may
comprise an adhesive material such as, e.g., a glue, an epoxy, a
polymer, combinations of these, or the like, and may be applied by
initially applying an amount of the adhesive material to the first
insulating layer 1013, placing the structure support 1070 in
contact with the adhesion layer 1071, and then curing the adhesion
layer 1071 in order to solidify the connection between the
structure support 1070 and the first insulating layer 1013.
[0027] FIG. 1E illustrates a top view of the components shown in
FIG. 1D. As illustrated, the first opening 1012 is formed through
the second dielectric layer 1017 (although underneath the underfill
1020) to separate the first portion 1014 and the second portion
1016 of the flexible substrate 1010, although the flexible
substrate 1010 may extend around the first opening 1012 above and
below (in FIG. 1E) the first opening 1012. The die 1030 is placed
within the first opening 1012 and the structure support 1070 is
attached to the opposite side of the flexible substrate 1010 to
provide additional support against thermal expansion.
[0028] Additionally, while the first opening 1012 is illustrated in
FIG. 1E as being an opening through second dielectric layer 1017 to
expose a portion of the first RDL 1015, this is intended to be
illustrative and is not intended to be limiting. Rather, any
suitable pattern for the first opening 1012, including removing
portions of the second dielectric layer 1017 all the way across the
substrate 1013 such that the second dielectric layer 1017 is
separated into two completely different portions that are
unconnected, may alternatively be utilized. All such patterns are
fully intended to be included within the scope of the
embodiments.
[0029] FIGS. 2A-2D illustrate in cross-sectional views a process of
forming the package 1000 with a flexible substrate 1010 comprising
five layers. In this embodiment, the flexible substrate 1010 has
multiple RDLs, compared to only the first RDL 1015 shown in FIGS.
1A-1D. The following descriptions highlight the differences between
FIGS. 2A-2D and FIGS. 1A-1D.
[0030] FIG. 2A illustrates the flexible substrate 1010 with five
layers. The flexible substrate 1010 comprises the first insulating
layer 1013 which is a bottom insulating layer, the first RDL 1015
formed on the first insulating layer 1013 at a first side, and the
second insulating layer 1017 above the first RDL 1015. The details
of the first insulating layer 1013, the first RDL 1015, and the
second insulating layer 1017 are similar to the descriptions for
the FIGS. 1A-1D.
[0031] The flexible substrate 1010 further comprises a second RDL
1019 above the second insulating layer 1017, followed by a third
insulating layer 1021 which is also the top insulating layer on the
second RDL 1019. There may be more insulating layers and RDLs
formed for the flexible substrate 1010, which are not shown. The
insulating layers and RDLs may be formed in an alternating fashion
so that a RDL is between two insulating layers. The third
insulating layer 1021 at the top surface of the flexible substrate
1010 and the first insulating layer 1013 at the bottom surface of
the flexible substrate 1010 are insulating layers to provide
protections to the flexible substrate 1010. The various insulating
layers, such as the first insulating layer 1013, the second
insulating layer 1017, and the third insulating layer 1021 may be
made of a same material or of different materials. The various
RDLs, such as the first RDL 1015 and the second RDL 1019 may be
made of a same material or of a different material.
[0032] The heights or thicknesses of the various insulating layers
and RDLs may be different. For example, the third insulating layer
1021 may be similar to the first insulating layer 1013 and may have
a fifth height H.sub.5 in a range from about 15 .mu.m to about 20
.mu.m, while the second RDL 1019 in the middle of the stack may
have a sixth height H.sub.6 that may be in a range from about 10
.mu.m to about 24 .mu.m, such as being either between 10 .mu.m and
about 12 .mu.m (which is thinner than the bottom and the top
insulating layers) or being between about 20 .mu.m and 24 .mu.m
(similar to the first RDL 1015). As such, the second RDL 1019 may
have a ratio to the first height H.sub.1 of between about 0.5 and
about 1.6, a ratio to the second height H.sub.2 of between about
0.4 and about 1.2, a ratio to the third height H.sub.3 of between
about 0.25 and about 0.8, and a ratio to the fourth height H.sub.4
of between about 0.1 and about 1.2. All the numbers are for
examples only and are not limiting. With the continuous reduction
in feature sizes for semiconductor devices, it is possible the
first RDL 1015, the second RDL 1019, the first insulating layer
1013, the second insulating layer 1017, and the third insulating
layer 1021, may have smaller heights than described above.
[0033] FIG. 2B illustrates the first opening 1012 of the flexible
substrate 1010, formed at the first side of the first insulating
layer 1013, through the second insulating layer 1017, the second
RDL 1019, and the third insulating layer 1021. In this embodiment,
the first opening 1012 may be formed through the plurality of
insulating layers and RDLs except the first insulating layer 1013
and the first RDL 1015. The first opening 1012 exposes the first
RDL 1015 so that the die 1030 may be connected to the first RDL
1015 within the first opening 1012 as shown in FIGS. 2C-2D. The
first opening 1012 may be formed around the middle of the flexible
substrate 1010 so that the first portion 1014 and the second
portion 1016, (separated by the first opening 1012 of the second
insulating layer 1017, the second RDL 1019, and the third
insulating layer 1021), are of a substantially similar length. The
length of the first opening 1012 may be slightly larger than a
length of the die 1030 which is going to be placed within the first
opening 1012.
[0034] FIGS. 2C-2D illustrate the placement of the die 1030 on the
flexible substrate 1010 with five layers shown in FIG. 2A to form
the package 1000 using the connector 1050 or a plurality of
connectors 1050, with FIG. 2C illustrating the package 1000 formed
using solder balls as the connector 1050, and FIG. 2D illustrating
the package 1000 formed using metal pillars as the connector 1050.
The package 1000 further comprises the die RDL 1110, the underfill
1020, the adhesion layer 1071, and the structure support 1070. The
details of the connectors 1050, the die 1030, the die RDL 1110, the
underfill 1020, the adhesion layer 1071, and the structure support
1070 may be similar to the description above with respect to FIGS.
1C-1D. The total height of the package 1000 shown in FIGS. 2C-2D
may be in a range from about 190 .mu.m to about 210 .mu.m, such as
200 .mu.m.
[0035] Having more layers of conductive materials and insulating
materials can provide more structure support to the die 1030, and
more flexibility as to how the conductive connections are made
among the multiple RDLs. The additional layers may also enable more
applications when the package 1000 may be used. The five layers
shown in FIGS. 2A-2D are merely examples of multiple layers of
conductive materials and insulating materials. There may be even
more than five layers shown in FIGS. 2A-2D.
[0036] FIGS. 3A-3B illustrate in cross-sectional view yet another
embodiment in which a package is formed on a five layer flexible
substrate with openings on both sides. FIG. 3A illustrates the
flexible substrate 1010 comprising the first insulating layer 1013,
the first RDL 1015 formed on the first insulating layer 1013 at the
first side, and the second insulating layer 1017 above the first
RDL 1015. However, in this embodiment, the flexible substrate 1010
further comprises the second RDL 1019 next to the first insulating
layer 1013 at the second side opposite to the first side of the
first insulating layer 1013, and the third insulating layer 1021
next to the second RDL 1019. There may be more insulating layers
and RDLs formed for the flexible substrate 1010, which are not
shown. The insulating layers and RDLs may be formed in an
alternating fashion so that a RDL is between two insulating layers.
The first insulating layer 1013, the second insulating layer 1017,
and the third insulating layer 1021 may be made of a same material
or of different materials. The first RDL 1015 and the second RDL
1019 may be made of a same material or of a different material.
[0037] The flexible substrate 1010 further comprises the first
opening 1012 formed at the first side of the first insulating layer
1013, through the second insulating layer 1017. The flexible
substrate 1010 further comprises a second opening 1022 formed at
the second side of the first insulating layer 1013 opposite to the
first side, through the second RDL 1019 and the third insulating
layer 1021. In general, the second opening 1022 may be formed
through a plurality of insulating layers and RDLs to expose the
second side of the first insulating layer 1013, although in other
embodiments, the second opening 1022 may be shallower and not reach
the first insulating layer 1013. The second opening 1022 provides
more space where the structure support 1070 may be placed, while
not increasing the overall height of the package 1000 as shown in
FIG. 3B. The second opening 1022 may be formed around the middle of
the flexible substrate 1010 so that the first portion 1014 and the
second portion 1016 are separated by the second opening 1022 of the
third insulating layer 1021 and the second RDL 1019, are of a
substantially similar length. The length of the second opening 1022
may be of similar length of the first opening 1012.
[0038] As illustrated in FIG. 3B, the die 1030 may be placed on the
flexible substrate 1010 to form the package 1000. The package 1000
comprises the connector 1050, the die 1030 with the die RDL 1110,
and the underfill 1020 filling the first opening 1012. The details
of the connectors 1050, the die 1030, the die RDL 1110, and the
underfill 1020 may be similar as described above with respect to
FIGS. 1A-1D and FIGS. 2A-2D.
[0039] The package 1000 may further comprise the structure support
1070 connected to the first insulating layer 1013 at a second side
opposite to the first side of the first insulating layer 1013,
placed within the second opening 1022 of the flexible substrate
1010. The structure support 1070 is connected to the first
insulating layer 1013 by the adhesion layer 1071. The structure
support 1070 may or may not fill the second opening 1022. The
second opening 1022 provides more space where the structure support
1070 may be placed, while not increasing the overall height of the
package 1000.
[0040] FIGS. 4A-4C illustrate in cross-sectional views a process of
placing the die 1030 on the flexible substrate 1010 with five
layers to form the package 1000, in accordance with some additional
embodiments. In this embodiment, the flexible substrate 1010 is
separated into the first portion 1014 and the second portion 1016.
Similar structures may be formed for a flexible substrate 1010 with
other numbers of layers such as three layers or seven layers, which
are not shown.
[0041] As illustrated in FIG. 4A, the flexible substrate 1010 may
comprise the first insulating layer 1013, the first RDL 1015 formed
on the first insulating layer 1013 at a first side, and the second
insulating layer 1017 above the first RDL 1015. The flexible
substrate 1010 further comprises the second RDL 1019 above the
second insulating layer 1017, and the third insulating layer 1021
above the second RDL 1019. There may be more insulating layers and
RDLs formed for the flexible substrate 1010, which are not
shown.
[0042] The flexible substrate 1010 may have the first opening 1012
and a third opening 1032. The first opening 1012 is through the
second insulating layer 1017, the second RDL 1019, and the third
insulating layer 1021. The third opening 1032 is through the first
insulating layer 1013 and the first RDL 1015. The first opening
1012 and the third opening 1032 are connected and cut the flexible
substrate 1010 into two completely separate portions, the first
portion 1014 and the second portion 1016, which are not physically
connected to each other. The third opening 1032 is narrower than
the first opening 1012, such as between about 10% to about 20%
narrower, therefore leaving a part of the first RDL 1015 exposed on
the first portion 1014 and the second portion 1016.
[0043] In an alternative embodiment, the first opening 1012 and the
third opening 1032 may be formed as openings made into the flexible
substrate 1010. In this embodiment the first opening 1012 and the
third opening 1032 connect to each other as openings through the
flexible substrate 1010 but portions of the flexible substrate 1010
not within the first portion 1014 or the second portion 1016 may
remain in contact with each other. As such, the first opening 1012
and the third opening 1032 form openings but do not fully separate
the flexible substrate 1010 into separate parts.
[0044] The die 1030 with the die RDL 1110 may be placed on the
flexible substrate 1010 to form the package 1000. The connector
1050 is placed on the first portion 1014, and the connector 1050 is
placed on the second portion 1016. The package 1000 further
comprises the underfill 1020 filling the first opening 1012. The
details of the connectors 1050, the die 1030, the die RDL 1110, and
the underfill 1020 may be similar as described above with respect
to FIGS. 1A-1D and FIGS. 2A-2D.
[0045] The package 1000 further comprises the structure support
1070 connected to the first insulating layer 1013 at a second side
opposite to the first side at the first portion 1014, and the
structure support 1070 connected to the first insulating layer 1013
at a second side opposite to the first side at the second portion
1016. The structure support 1070 is connected to the first
insulating layer 1013 by the adhesion layer 1071. This embodiment
may provide more flexibility for the die 1030 while still providing
support to the die 1030 as well.
[0046] Alternatively, as shown in FIG. 4C, the structure support
1070 may be attached so that the structure support 1070 crosses the
third opening 1032. In this embodiment the adhesion layer 1071 may
be initially applied to the first portion 1014 and the second
portion 1016 and then the structure support 1070 may be placed on
the adhesion layer 1071 such that the structure support 1070 covers
the third opening 1032. Such an embodiment provides for additional
support between the first portion 1014 and the second portion
1016.
[0047] Optionally if desired, a second underfill 1073 may be placed
into the third opening 1032 in order to provide an additional
amount of support. In an embodiment the second underfill 1073 may
be similar to the underfill 1020 described above with respect to
FIG. 1C, although the second underfill 1073 may alternatively be
different. The second underfill 1073 may be placed into the third
opening prior to the attachment of the structure support 1070 to
the flexible substrate 1010.
[0048] A package device is disclosed. The package device comprises
a flexible substrate having a first insulating layer, a first RDL
on the first insulating layer at a first side, and a second
insulating layer on the first RDL. A first opening of the flexible
substrate is formed through the second insulating layer, separating
the second insulating layer into a first portion and a second
portion. One or more connectors are placed within the first opening
of the flexible substrate and in contact with the first RDL. A die
is on the one or more connectors and electrically connected to the
one or more connectors.
[0049] A method for forming a package device is disclosed. The
method comprises forming a first opening in a flexible substrate,
wherein the flexible substrate comprises a first insulating layer,
a first RDL on the first insulating layer at a first side, and a
second insulating layer on the first RDL, and the first opening is
through the second insulating layer. The method further places a
connector within the first opening of the flexible substrate and in
contact with the first RDL; and places a die on the connector and
electrically connected to the connector.
[0050] A package device is disclosed. The package device comprises
a flexible substrate having a first insulating layer, a first RDL
on the first insulating layer at a first side, and a second
insulating layer on the first RDL. A first opening of the flexible
substrate is formed through the second insulating layer, separating
the second insulating layer into a first portion and a second
portion. A connector is placed within the first opening of the
flexible substrate and in contact with the first RDL. A die on the
connector and electrically connected to the connector. A structure
support is connected to the first insulating layer at a second side
opposite to the first side of the first insulating layer.
[0051] Although the present disclosure and its advantages have been
described in detail, it should be understood that various changes,
substitutions and alterations can be made herein without departing
from the spirit and scope of the disclosure as defined by the
appended claims. Moreover, the scope of the present application is
not intended to be limited to the particular embodiments of the
process, machine, manufacture, and composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the present
disclosure, processes, machines, manufacture, compositions of
matter, means, methods, or steps, presently existing or later to be
developed, that perform substantially the same function or achieve
substantially the same result as the corresponding embodiments
described herein may be utilized according to the present
disclosure. Accordingly, the appended claims are intended to
include within their scope such processes, machines, manufacture,
compositions of matter, means, methods, or steps. In addition, each
claim constitutes a separate embodiment, and the combination of
various claims and embodiments are within the scope of the
disclosure.
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