U.S. patent application number 13/782109 was filed with the patent office on 2014-05-15 for warpage control for flexible substrates.
This patent application is currently assigned to TAIWAN SEMICONDUCTOR MANUFACTURING COMPANY, LTD.. The applicant listed for this patent is Taiwan Semiconductor Manufacturing Company, Ltd.. Invention is credited to Shang-Yun Hou, Jing-Cheng Lin, Shih Ting Lin, Szu Wei Lu, Chen-Hua Yu.
Application Number | 20140131897 13/782109 |
Document ID | / |
Family ID | 50680954 |
Filed Date | 2014-05-15 |
United States Patent
Application |
20140131897 |
Kind Code |
A1 |
Yu; Chen-Hua ; et
al. |
May 15, 2014 |
Warpage Control for Flexible Substrates
Abstract
A flexible substrate may be provided having a first side and a
second side. A device may be electrically coupled to the first side
of the flexible substrate through one or more electrical
connections. A warpage control device may be attached to the second
side flexible substrate. The warpage control device may include an
adhesive layer and a rigid layer. The warpage control device may be
formed in an area of the second side of the flexible substrate that
may be opposite the one or more electrical connections on the first
side of the flexible substrate.
Inventors: |
Yu; Chen-Hua; (Hsin-Chu,
TW) ; Lin; Shih Ting; (Taipei City, TW) ; Lin;
Jing-Cheng; (Hsin-Chu, TW) ; Hou; Shang-Yun;
(Jubei City, TW) ; Lu; Szu Wei; (Hsin-Chu,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Manufacturing Company, Ltd.; Taiwan Semiconductor |
|
|
US |
|
|
Assignee: |
TAIWAN SEMICONDUCTOR MANUFACTURING
COMPANY, LTD.
Hsin-Chu
TW
|
Family ID: |
50680954 |
Appl. No.: |
13/782109 |
Filed: |
March 1, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61726824 |
Nov 15, 2012 |
|
|
|
Current U.S.
Class: |
257/783 ;
438/118 |
Current CPC
Class: |
H01L 2224/05611
20130101; H01L 2224/05644 20130101; H01L 2224/05794 20130101; H01L
2224/81424 20130101; H01L 23/5387 20130101; H01L 2224/0401
20130101; H01L 2224/133 20130101; H01L 2224/13294 20130101; H01L
24/05 20130101; H01L 2924/3511 20130101; H01L 2224/133 20130101;
H01L 2224/05794 20130101; H01L 2224/05624 20130101; H01L 2224/058
20130101; H01L 2224/13144 20130101; H01L 2224/831 20130101; H01L
21/561 20130101; H01L 24/92 20130101; H01L 2224/05609 20130101;
H01L 2224/81192 20130101; H01L 24/32 20130101; H01L 2224/32225
20130101; H01L 2224/81444 20130101; H01L 2224/81007 20130101; H01L
2224/81409 20130101; H01L 2924/01322 20130101; H01L 2224/81409
20130101; H01L 2224/131 20130101; H01L 2224/81424 20130101; H01L
2224/81411 20130101; H01L 2224/73204 20130101; H01L 2224/81447
20130101; H01L 24/81 20130101; H01L 2224/81444 20130101; H01L
2224/13147 20130101; H01L 2924/01322 20130101; H01L 2224/05647
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2224/81815 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2924/01029 20130101; H01L 2924/01032 20130101; H01L
2924/01032 20130101; H01L 2924/01029 20130101; H01L 2924/00014
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2924/00 20130101; H01L 2924/00014 20130101; H01L 2924/00014
20130101; H01L 2924/00014 20130101; H01L 2924/014 20130101; H01L
2924/014 20130101; H01L 2924/014 20130101; H01L 2924/00014
20130101; H01L 2924/00014 20130101; H01L 2924/00014 20130101; H01L
2924/00014 20130101; H01L 2924/00014 20130101; H01L 2224/16
20130101; H01L 24/83 20130101; H01L 21/563 20130101; H01L
2224/05611 20130101; H01L 2224/058 20130101; H01L 2224/13109
20130101; H01L 2224/05624 20130101; H01L 2224/05609 20130101; H01L
2224/831 20130101; H01L 2224/13147 20130101; H01L 24/16 20130101;
H01L 23/4985 20130101; H01L 2224/13111 20130101; H01L 2224/05644
20130101; H01L 2224/131 20130101; H01L 2224/13144 20130101; H01L
21/56 20130101; H01L 2224/05624 20130101; H01L 2224/05647 20130101;
H01L 2224/13294 20130101; H01L 2224/92125 20130101; H01L 2224/13109
20130101; H01L 2224/81447 20130101; H01L 23/562 20130101; H01L
2224/13111 20130101; H01L 2224/81193 20130101; H01L 2224/81411
20130101; H01L 2224/81424 20130101; H01L 2224/83007 20130101; H01L
24/13 20130101 |
Class at
Publication: |
257/783 ;
438/118 |
International
Class: |
H01L 21/58 20060101
H01L021/58; H01L 23/498 20060101 H01L023/498 |
Claims
1. A method for providing a flexible structure, comprising:
providing a flex substrate having a plurality of electrical
connections formed on a first side of the flex substrate; and
attaching an adhesive layer and a rigid layer to a second side of
the flex substrate, wherein the adhesive layer and the rigid layer
are attached to an area of the second side of the flex substrate
opposing the one or more electrical connections on the first side
of the flex substrate.
2. The method of claim 1, wherein the rigid layer is a metal, a
plastic, a polymer or combinations thereof.
3. The method of claim 1, further comprising: prior to the
attaching the adhesive layer and the rigid layer to the second side
of the flex substrate, attaching a device to the electrical
connections on the first side of the flex substrate.
4. The method of claim 1, further comprising: after the attaching
the adhesive layer and the rigid layer to the second side of the
flex substrate, attaching a device to the electrical connections on
the first side of the flex substrate.
5. The method of claim 1, wherein the attaching the adhesive layer
and the rigid layer to the second side of the flex substrate
comprises: attaching the adhesive layer to the second side of the
flex substrate; and after the attaching the adhesive layer,
attaching the rigid layer to the adhesive layer.
6. The method of claim 1, wherein the attaching the adhesive layer
and the rigid layer to the second side of the flex substrate
comprises: forming the adhesive layer on the rigid layer; and after
the forming the adhesive layer on the rigid layer, attaching the
adhesive layer and the rigid layer to the flex substrate to the
second side of the flex substrate.
7. The method of claim 1, wherein the attaching the adhesive layer
includes pressing, spraying, brushing or laminating the adhesive
layer to the flex substrate.
8. The method of claim 1, wherein the flex substrate is a polymer,
a polyimide, a plastic, a transparent conductive film or
combinations thereof.
9. The method of claim 1, wherein the rigid layer comprises a
plurality of layers.
10. A method for providing a flexible structure, comprising:
attaching a device to one or more electrical connections on a first
side of a flex substrate; and attaching an adhesive layer and a
rigid layer on a second side of the flex substrate, wherein the
adhesive layer is attached to an area of the second side of the
flex substrate opposing the one or more electrical connections.
11. The method of claim 10, further comprising: forming a molding
underfill between the device and the flex substrate.
12. The method of claim 10, wherein the attaching the adhesive
layer and the rigid layer to the second side of the flex substrate
comprises: attaching the adhesive layer to the second side of the
flex substrate; and following the attaching the adhesive layer,
attaching the rigid layer to the adhesive layer.
13. The method of claim 10, wherein the attaching the adhesive
layer and the rigid layer to the second side of the flex substrate
comprises: forming the adhesive layer on the rigid layer; and
attaching the adhesive layer and the rigid layer to the second side
of the flex substrate.
14. The method of claim 10, wherein the rigid layer is a metal, a
plastic, a polymer or combinations thereof.
15. The method of claim 10, wherein the device is a packaged
semiconductor device, a die or an interposer.
16-20. (canceled)
21. A method comprising: forming on a first surface of a flex
substrate a first plurality of electrical connectors; attaching to
a second surface of the flex substrate, opposite the first surface,
a rigid layer; aligning a second plurality of electrical connectors
on a device to respective ones of the first plurality of electrical
connectors; reflowing the first and second plurality of electrical
connectors; and forming an underfill between the device and the
first surface of the flex substrate.
22. The method of claim 21, further comprising: prior to attaching
to the second surface of the flex substrate the rigid layer,
forming on the rigid layer an adhesive layer using a process
selected from the group consisting of: laminating, spraying,
dipping, brushing, and combinations thereof.
23. The method of claim 22, wherein one of the first plurality of
connectors and the second plurality of connectors comprise solder
bumps.
24. The method of claim 22, wherein the step of attaching to a
second surface of the flex substrate, opposite the first surface, a
rigid layer occurs prior to the step of aligning a second plurality
of electrical connectors on a device to respective ones of the
first plurality of electrical connector.
25. The method of claim 22, further comprising testing the device.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of U.S. Provisional
Application Ser. No. 61/726,824, filed on Nov. 15, 2012, entitled
"Warpage Control for Flexible Substrates," which application is
hereby incorporated herein by reference.
BACKGROUND
[0002] A flexible substrate (also referred herein to as a "flex"
substrate) is a substrate that provides for flexible movement. Flex
substrates provide advantages over non-flexible substrates in
applications where a device may be subjected to movements such as
bending, twisting or the like. Semiconductor devices, integrated
circuits or the like can be electrically coupled to flex
substrates. Differences in material properties between a flex
substrate and a device being coupled to the flex substrate can
degrade electrical connections between the device and the flex
substrate. For example, differences between coefficients of thermal
expansion for a flex substrate and for a device electrically
coupled to the flex substrate can cause strain on the electrical
connections between the device and the flex substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] For a more complete understanding of the present
embodiments, and the advantages thereof, reference is now made to
the following descriptions taken in conjunction with the
accompanying drawings, in which:
[0004] FIGS. 1A-1D illustrate cross-sectional views of intermediate
stages of forming a warpage control device according to an
embodiment;
[0005] FIGS. 2A-2D illustrate cross-sectional views of intermediate
stages of forming a warpage control device according to another
embodiment; and
[0006] FIGS. 3A-3B illustrate cross-sectional views of various
warpage control devices according to various embodiments.
DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS
[0007] The making and using of the embodiments are discussed in
detail below. It should be appreciated, however, that the present
disclosure provides many applicable inventive 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 invention, and do not limit the scope of the
invention.
[0008] In general terms, embodiments provide a warpage control
device that limits warpage or bow of a flex substrate. The warpage
control device may be applied either prior to or following a reflow
process wherein a device may be electrically coupled to the flex
substrate. The warpage control device may provide support for the
flex substrate to aid in maintaining the integrity of electrical
connections between a device and a flex substrate throughout
various manufacturing, fabrication and/or testing processes. The
warpage control device may also provide support for the flex
substrate to aid in maintaining the integrity of electrical
connections between a device and a flex substrate in various
operating environments, conditions or applications.
[0009] FIGS. 1A-1D illustrate cross-sectional views of intermediate
stages of forming a warpage control device 140 according to an
embodiment. As illustrated in FIGS. 1A-1B, a flex substrate 110 may
include a first side 110a and a second side 110b. In an embodiment,
a plurality of solder bumps and/or bonding pads 112 may be formed
on the first side 110a of the flex substrate. An adhesive layer 120
and a rigid layer 130, which together may comprise the warpage
control device 140, may be attached to the second side 110b of the
flex substrate 110. In an embodiment, the warpage control device
140 may be formed on an area of the second side 110b that may be
opposite the plurality of solder bumps and/or bonding pads 112
formed on the first side 110a of the flex substrate 110.
[0010] In various embodiments, the flex substrate 110 may comprise
polymer films, such as polyethylene terephthalate, kapton,
polyimide or the like, flexible plastic substrates, transparent
conductive polyester films or other like materials. In various
embodiments, the adhesive layer 120 may comprise epoxy, a polymer,
glue, an adhesive agent or the like disposed between the rigid
layer 130 and the flex substrate 110. In various embodiments, the
rigid layer 130 may comprise a metal, a plastic, a polymer, a
semiconductor material, a quartz, a ceramic or other material that
may provide a rigid or semi-rigid support to the flex substrate
110. For example, a material may be chosen for the rigid layer 130
that may have a higher bulk modulus as compared to that of the flex
substrate 110. In an embodiment, the rigid layer 130 may comprise a
plurality of layers (not shown).
[0011] As illustrated in FIGS. 1A-1B, the warpage control device
140 may, in an embodiment, be attached to the flex substrate 110
before electrically coupling another device (discussed below) to
the flex substrate 110. Placing the warpage control device 140 on
the flex substrate 110 before electrically coupling the other
device (discussed below) to the flex substrate 110 may aid in
minimizing warpage or bow of the flex substrate 110 during the
electrical coupling of the other device (discussed below) and/or
subsequent manufacturing processes.
[0012] The methods for attaching the warpage control device 140 on
the flex substrate 110 may vary. In one embodiment, for example,
the adhesive layer 120 may first be formed on the second side 110b
of flex substrate 110 and then the rigid layer 130 may be applied
to the adhesive layer 120. In various embodiments, the adhesive
layer 120 may be formed on the second side 110b of the flex
substrate 110 using processes such as, for example, lamination,
spraying, dipping, brushing or the like. In such embodiments, the
rigid layer 130 may, for example, be pressed, fused, laminated,
affixed or applied onto the adhesive layer 120 to form the warpage
control device 140.
[0013] In another embodiment, for example, the adhesive layer 120
may first be formed on the rigid layer 130 and then the combined
adhesive layer 120 and rigid layer 130 may be attached to the
second side 120b of the flex substrate 110 to form the warpage
control device 140. In various embodiments, the adhesive layer 120
may be formed on the rigid layer 130 using processes such as, for
example, lamination, spraying, dipping, brushing or the like. In
such embodiments, the rigid layer 130 and the adhesive layer 120,
together, may be pressed, fused, laminated, affixed or applied onto
the second side 110b of the flex substrate 110 to form the warpage
control device 140.
[0014] As illustrated in FIGS. 1C-1D, a device 150 may be coupled
to the flex substrate 110 following attachment of the warpage
control device 140 thereon. As shown in FIG. 1C, the device 150 may
include solder bumps or bonding pads 152 formed thereon. The device
150 may be aligned with and placed upon corresponding solder bumps
or bonding pads 112 on the flex substrate 110. In various
embodiments, the device 150 may be a packaged semiconductor device,
an interposer, a die, a wafer, another flex substrate, a
non-flexible substrate or other like material. In various
embodiments, the solder bumps or bonding pads 152 on the device may
comprise metals including, but not limited to, a eutectic alloy
such as AlCu, AlGe or a low-melting point metal layer such as In,
Au, Sn, Cu, lead free solder, solder paste or other like
material.
[0015] As shown in FIG. 1D, a reflow process may be performed to
couple the device 150 to the flex substrate 110 through a plurality
of electrical connections 170. During the reflow process, the
warpage control device 140 may aid in minimizing warpage or bow of
the flex substrate 110. Also shown in FIG. 1D, a molding underfill
160 may be formed between the device 150 and the first side 110a of
the flex substrate. The molding underfill 160 may further aid in
minimizing warpage or bow of the flex substrate 110 during
subsequent manufacturing processes.
[0016] In various embodiments, the solder bumps and/or bonding pads
112 on the first side 110a of the flex substrate 110 may comprise
metals including, but not limited to, a eutectic alloy such as
AlCu, AlGe or a low-melting point metal layer such as In, Au, Sn,
Cu or other like material.
[0017] FIGS. 2A-2D illustrate various intermediate stages of
forming a warpage control device in accordance with another
embodiment. As shown in FIGS. 2A-2B, a flex substrate 210 may
include a first side 210a and a second side 210b. A device 220 may
be electrically coupled to the flex substrate 210 through a
plurality of connections 230 on the first side 210a of the flex
substrate 210. FIG. 2B illustrates the configuration of FIG. 2A
after a molding underfill 240 may be formed between the device 220
and the first side 210a of the flex substrate 210.
[0018] As shown in FIG. 2C-2D, a warpage control device 270 may be
attached on the second side 210b of the flex substrate 210. The
warpage control device 270 may include an adhesive layer 250 and a
rigid layer 260. In an embodiment, the warpage control device 270
may be formed on an area of the second side 210b that may be
opposite the device 220 formed on the first side 210a of the flex
substrate 210. In comparison to the embodiment illustrated in FIGS.
1A-1D in which the warpage control device 140 is attached to the
flex substrate 110 before coupling the device 150 to the flex
substrate 110, the embodiment as illustrated in Figures 2A-2D
provides for attaching the warpage control device 270 to the flex
substrate 210 after coupling the device 220 to the flex substrate
210.
[0019] The methods for attaching the warpage control device 270 on
the flex substrate 210 may vary. In one embodiment, for example,
the adhesive layer 250 may first be formed on the second side 210b
of flex substrate 110 and then the rigid layer 260 may be attached
to the adhesive layer 250. In various embodiments, the adhesive
layer 250 may be formed on the second side 210b of the flex
substrate 210 using processes such as, for example, lamination,
spraying, dipping, brushing or the like. In such embodiments, the
rigid layer 260 may be pressed, fused, laminated, affixed or
applied onto the adhesive layer 250 to form the warpage control
device 270.
[0020] In another embodiment, for example, the adhesive layer 250
may first be formed on the rigid layer 260 and then the combined
adhesive layer 250 and rigid layer 260 may be attached to the
second side 120b of the flex substrate 210 to form the warpage
control device 270. In various embodiments, the adhesive layer 250
may be formed on the rigid layer 260 using processes such as, for
example, lamination, spraying, dipping, brushing or the like. In
such embodiments, the rigid layer 260 and the adhesive layer 250,
together, may be pressed, laminated, fused, affixed or applied onto
the second side 210b of the flex substrate 210 to form the warpage
control device 270.
[0021] As illustrated in FIGS. 2A-2D, the device 220 may be coupled
to the flex substrate 210 before the warpage control device 270 may
be formed on the flex substrate 210. The order of forming a warpage
control device on a flex substrate may depend on manufacturing
processes and/or device types that may be coupled to the flex
substrate on the opposite side of the flex substrate. The
embodiments as shown in FIGS. 1A-1D and 2A-2D are provided to
illustrate that the order of forming a warpage control device on a
flex substrate may be varied, as determined by design and/or
manufacturing processes involving the flex substrate.
[0022] The present disclosure provides for other warpage control
device configurations. FIGS. 3A-3B illustrate cross-sectional views
of various warpage control devices according to various
embodiments. As shown in FIG. 3, a flex substrate 310 may include a
first side 310a and a second side 310b. A plurality of electrical
connections 311 may be formed on the first side 310a between a
device 312 and the flex substrate 310. A molding underfill 313 may
be formed between the device 312 and the first side 310a of the
flex substrate 310. A warpage control device 316 may be attached to
an area of the second side 310b that may be opposite the device 312
formed on the first side 310a of the flex substrate 310. The
warpage control device 316 may include an adhesive layer 314 and a
plurality of layers, shown here as a first layer 315.1 and a second
layer 315.2. In various embodiments, the plurality of layers may be
rigid layers, semi-rigid layers, heat-sinks or the like. The
plurality of layers may be attached together using similar methods
similar attaching methods as those discussed herein.
[0023] FIG. 3B illustrates a cross-sectional view of a plurality of
warpage control devices on a flex substrate 320 according to an
embodiment. As shown in FIG. 3B, the flex substrate 320 may include
a first side 320a and a second side 320b. A plurality of electrical
connections 321 may be formed between a device 322 and the flex
substrate 320 on the first side 320a of the flex substrate 320. A
molding underfill 323 may be formed between the device 322 and the
first side 320a of the flex substrate 320.
[0024] A first warpage control device 330, which may include a
first adhesive layer 331 and a first rigid layer 332, may be
attached to the second side 320b of the flex substrate 320. The
first warpage control device 330 may be formed in an area of the
second side 320b that may be opposite the device 322 formed on the
first side 320a of the flex substrate 320.
[0025] As shown in FIG. 3B, the flex substrate 320 may be bent in a
manner to double-back on itself. In an embodiment a second warpage
control device 340, which may include a second adhesive layer 341
and a second rigid layer 342, may also be attached to the second
side 320b of the flex substrate. The second warpage control device
340 may be formed in an area of the second side 320b that may
approximately align with the first warpage control device 330 when
the flex substrate 320 is bent backwards on itself as shown in FIG.
3B.
[0026] The second warpage control device 340 may provide additional
support to aid in maintaining the integrity of the electrical
connections 321 between the device 322 and the flex substrate 320
through applications where one or more forces may be applied that
may press the flex substrate 320 together. Such applications may
include, for example, touch screen applications, touch pad
applications, press-key applications or other applications. In an
embodiment, the second warpage control device in a similar area,
but may be located on the first side 320a of the flex
substrate.
[0027] In an embodiment, a method is provided. The method may
include providing a flex substrate having a plurality of electrical
connections formed on a first side of the flex substrate; and
attaching an adhesive layer and a rigid layer to a second side of
the flex substrate, wherein the adhesive layer and the rigid layer
are attached to an area of the second side of the flex substrate
opposing the one or more electrical connections on the first side
of the flex substrate.
[0028] In another embodiment, another method is provided. The
method may include attaching a device to one or more electrical
connections on a first side of a flex substrate; and attaching an
adhesive layer and a rigid layer on a second side of the flex
substrate, wherein the adhesive layer is attached to an area of the
second side of the flex substrate opposing the one or more
electrical connections.
[0029] In an embodiment, an apparatus is provided. The apparatus
may comprise a flex substrate having a first side and a second
side; one or more electrical connections on the first side of the
flex substrate; a first rigid layer on the second side of the flex
substrate, wherein the first rigid layer is positioned in an area
of the second side opposing the one or more electrical connections
on the first side of the flex substrate; and a first adhesive layer
between the first rigid layer and the second side of the flex
substrate.
[0030] Although the present embodiments and their 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. For example, it will be readily understood by
those skilled in the art that the structures and ordering of steps
as described above may be varied while remaining within the scope
of the present disclosure.
[0031] Moreover, the scope of the present application is not
intended to be limited to the particular embodiments of the
process, machine, manufacture, composition of matter, means,
methods and steps described in the specification. As one of
ordinary skill in the art will readily appreciate from the
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.
* * * * *