U.S. patent application number 12/191258 was filed with the patent office on 2009-02-12 for electrochemically fabricated structures having dielectric or active bases and methods of and apparatus for producing such structures.
This patent application is currently assigned to Microfabrica Inc.. Invention is credited to Adam L. Cohen, Michael S. Lockard, Dennis R. Smalley, Jeffrey A. Thompson.
Application Number | 20090038948 12/191258 |
Document ID | / |
Family ID | 46205213 |
Filed Date | 2009-02-12 |
United States Patent
Application |
20090038948 |
Kind Code |
A1 |
Thompson; Jeffrey A. ; et
al. |
February 12, 2009 |
Electrochemically Fabricated Structures Having Dielectric or Active
Bases and Methods of and Apparatus for Producing Such
Structures
Abstract
Multilayer structures are electrochemically fabricated on a
temporary (e.g. conductive) substrate and are thereafter bonded to
a permanent (e.g. dielectric, patterned, multi-material, or
otherwise functional) substrate and removed from the temporary
substrate. In some embodiments, the structures are formed from top
layer to bottom layer, such that the bottom layer of the structure
becomes adhered to the permanent substrate, while in other
embodiments the structures are formed from bottom layer to top
layer and then a double substrate swap occurs. The permanent
substrate may be a solid that is bonded (e.g. by an adhesive) to
the layered structure or it may start out as a flowable material
that is solidified adjacent to or partially surrounding a portion
of the structure with bonding occurring during solidification. The
multilayer structure may be released from a sacrificial material
prior to attaching the permanent substrate or it may be released
after attachment.
Inventors: |
Thompson; Jeffrey A.; (Los
Angeles, CA) ; Cohen; Adam L.; (Los Angeles, CA)
; Lockard; Michael S.; (Lake Elizabeth, CA) ;
Smalley; Dennis R.; (Newhall, CA) |
Correspondence
Address: |
MICROFABRICA INC.;ATT: DENNIS R. SMALLEY
7911 HASKELL AVENUE
VAN NUYS
CA
91406
US
|
Assignee: |
Microfabrica Inc.
|
Family ID: |
46205213 |
Appl. No.: |
12/191258 |
Filed: |
August 13, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10841006 |
May 7, 2004 |
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12191258 |
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10434493 |
May 7, 2003 |
7250101 |
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10841006 |
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60442656 |
Jan 23, 2003 |
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60379177 |
May 7, 2002 |
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Current U.S.
Class: |
205/118 |
Current CPC
Class: |
B81C 2201/019 20130101;
B81C 1/00373 20130101; C25D 1/003 20130101; B81C 2201/0181
20130101 |
Class at
Publication: |
205/118 |
International
Class: |
C25D 5/02 20060101
C25D005/02 |
Claims
1. A fabrication process for producing a three-dimensional
structure from a plurality of adhered multi-material layers, the
process comprising: (A) forming a plurality of layers such that
successive layers are formed adjacent to and adhered to previously
formed layers and wherein a first layer is formed adjacent to and
adhered to a temporary substrate, wherein said forming of each of
the plurality of layers comprises: i) depositing at least one
sacrificial material, ii) depositing at least one structural
material, and iii) planarizing the at least one sacrificial
material and the at least one structural material to set a boundary
level of each layer; (B) after formation of at least two layers of
the plurality of layers, attaching a structural substrate
comprising a dielectric material to at least a portion of at least
one layer of the structure and removing at least a portion of the
temporary substrate from the structure; (C) before or after
attaching the structural substrate, or before or after removing the
temporary substrate, removing sacrificial material from a plurality
of layers to release the three-dimensional structure which is
formed from the structural material.
2. The process of claim 1 additionally comprising: (D) supplying a
plurality of preformed masks, wherein each mask comprises a
patterned dielectric material that includes at least one opening
through which deposition can take place during the depositing of
the at least one sacrificial material or the depositing of the at
least one structural material during forming of a given layer,
wherein each mask comprises a support structure that supports the
patterned dielectric material, wherein at least a plurality of the
depositing operations comprise: i) contacting the temporary
substrate and the dielectric material of a selected preformed mask;
ii) in presence of a plating solution, conducting an electric
current through the at least one opening in the selected mask
between an anode and a previously formed layer or the temporary
substrate, wherein the anode comprises a selected deposition
material, and wherein the previously formed layer or temporary
substrate functions as a cathode, such that the selected deposition
material is deposited onto the previously formed layer or temporary
substrate to form at least a portion of a layer; and iii)
separating the selected preformed mask from the temporary
substrate.
3. The process of claim 1 wherein a plurality of selective
depositing operations comprise: (1) providing an adhered patterned
mask on a surface of a previously formed layer or a surface of the
temporary substrate, wherein the mask includes at least one
opening; (2) in presence of a plating solution, conducting an
electric current through the at least one opening in the adhered
mask between an anode and the previously formed layer or the
substrate, wherein the anode comprises a selected deposition
material, and wherein the previously formed layer or the substrate
functions as a cathode, such that the selected deposition material
is deposited onto the previously formed layer or the temporary
substrate to form at least a portion of a given layer; and (3)
removing the mask from the previously formed layer or the temporary
substrate.
4. The process of claim 1 wherein the attaching comprises placing a
dielectric adhesive onto at least one of the structural substrate
or the at least portion of a bonding layer to which attachment is
to occur and then bringing the structural substrate and at least
portion of the bonding layer into contact.
5. The process of claim 1 wherein the structural substrate is a
preformed sheet that is bonded to the at least portion of the
bonding layer.
6. The process of claim 1 wherein the structural substrate
comprises a flowable material that is contacted to the at least
portion of the bonding layer and is thereafter allowed to solidify
or is made to solidify.
7. The process of claim 6 wherein the flowable material comprises a
pre-polymer.
8. The process of claim 7 wherein the pre-polymer comprises a
two-part epoxy.
9. The process of claim 1 wherein the structural substrate
comprises a flexible material.
10. The process of claim 1 wherein the attaching operation causes
the structural substrate to at least partially surround at least a
portion of the bonding layer of the three-dimensional
structure.
11. The process of claim 1 wherein the attaching of the structural
substrate to the three-dimensional structure comprises a mechanical
interlocking of portions of the structural substrate with portions
of the three-dimensional structure.
12. The process of claim 11 wherein at least one structural
material is deposited after depositing at least one sacrificial
material during the formation of a given layer.
13. The process of claim 11 wherein at least one sacrificial
material is deposited after depositing at least one structural
material.
14. The process of claim 13 wherein at least a portion of the at
least one sacrificial material is removed prior to attaching the
structural substrate.
15. The process of claim 14 wherein the at least portion of the
region from which sacrificial material that was removed is filled
with a dielectric material.
16. The process of claim 15 wherein the structural substrate
comprises the dielectric material.
17. The process of claim 13 wherein the structural substrate is
attached to the at least portion of the bonding layer prior to
removal of the sacrificial material.
18. The process of claim 13 wherein upon release of the structural
material from the sacrificial material the structural material is
also released from the temporary substrate.
19. The process of claim 1 wherein the structural substrate
comprises an electrical component.
20. The process of claim 1 wherein the structural substrate
comprises an integrated circuit.
21. The process of claim 1 wherein the attaching operation
comprises one or more wire bonding operations that attach one or
more portions of the structure to one or more portions of the
structural substrate.
22. The process of claim 1 wherein the attaching operation
comprises forming one or more reflowed solder contacts between one
or more portions of the structure and one or more portions of the
structural substrate.
23. The process of claim 1 wherein the temporary substrate
comprises a first temporary substrate and wherein the structural
substrate is attached after removing at least a portion of the
first temporary substrate from the structure, and wherein the
process additionally comprises: (D) after formation of at least two
layers attaching a second temporary substrate, which comprises a
plurality of materials and/or comprises a patterned structure, to
at least a portion of at least one layer of the structure and
thereafter removing at least a portion of the first temporary
substrate from the structure and then attaching the structural
substrate to at least a portion of a layer of the structure that at
least partially overlaps a location where the first temporary
substrate was attached.
24. A fabrication process for producing a multi-part
three-dimensional structure, wherein at least one part is formed
from a plurality of adhered multi-material layers, the process
comprising: (B) Forming at least one part of the multi-part
structure, comprising: i) forming a plurality of layers such that
successive layers are formed adjacent to and adhered to previously
formed layers and wherein a first layer is formed adjacent to and
adhered to a temporary substrate, wherein said forming of each of
the plurality of layers comprises: (1) depositing at least one
sacrificial material, (2) depositing at least one structural
material, and (3) planarizing the at least one sacrificial material
and the at least one structural material to set a boundary level of
each layer; ii) after formation of at least two layers of the
plurality of layers, attaching a structural substrate comprising a
dielectric material to at least a portion of at least one layer of
the structure and removing at least a portion of the temporary
substrate from the structure; (C) supplying at least one additional
part of the multi-part structure; (D) attaching the at least one
part to the at least one additional part to form the multi-part
structure; (E) removing the temporary substrate; (F) before or
after attaching the at least one part to the at least one
additional part, before or after removing the temporary substrate,
removing sacrificial material from a plurality of layers to release
the at least one part of the multi-layer part.
Description
RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 10/841,006, filed May 7, 2004, which in turn
is a continuation-in-part of U.S. patent application Ser. No.
10/434,493 filed on May 7, 2003 which in turn claims benefit of
U.S. Provisional Patent Application Nos. 60/442,656, and 60/379,177
filed on Jan. 23, 2003, and May 7, 2002 respectively. These
applications are incorporated herein by reference in their
entirety.
FIELD OF THE INVENTION
[0002] Various embodiments of some aspects of the present invention
relate generally to the field of Electrochemical Fabrication and
the associated formation of three-dimensional structures (e.g.
parts, objects, components, or devices) via a layer-by-layer build
up of deposited materials and to the processing of such structures
after layer formation is complete so that the structures are
transferred from a build substrate (i.e. temporary substrate) to a
structural substrate.
BACKGROUND
[0003] A technique for forming three-dimensional structures (e.g.
parts, components, devices, and the like) from a plurality of
adhered layers was invented by Adam L. Cohen and is known as
Electrochemical Fabrication. It is being commercially pursued by
Microfabrica.RTM. Inc. (formerly MEMGen Corporation) of Van Nuys,
Calif. under the name EFAB.RTM.. This technique was described in
U.S. Pat. No. 6,027,630, issued on Feb. 22, 2000. This
electrochemical deposition technique allows the selective
deposition of a material using a unique masking technique that
involves the use of a mask that includes patterned conformable
material on a support structure that is independent of the
substrate onto which plating will occur. When desiring to perform
an electrodeposition using the mask, the conformable portion of the
mask is brought into contact with a substrate while in the presence
of a plating solution such that the contact of the conformable
portion of the mask to the substrate inhibits deposition at
selected locations. For convenience, these masks might be
generically called conformable contact masks; the masking technique
may be generically called a conformable contact mask plating
process. More specifically, in the terminology of Microfabrica.RTM.
Inc. (formerly MEMGen Corporation) of Van Nuys, Calif. such masks
have come to be known as INSTANT MASKS.TM. and the process known as
INSTANT MASKING or INSTANT MASK.TM. plating. Selective depositions
using conformable contact mask plating may be used to form single
layers of material or may be used to form multi-layer structures.
The teachings of the '630 patent are hereby incorporated herein by
reference as if set forth in full herein. Since the filing of the
patent application that led to the above noted patent, various
papers about conformable contact mask plating (i.e. INSTANT
MASKING) and electrochemical fabrication have been published:
[0004] (1) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and
P. Will, "EFAB: Batch production of functional, fully-dense metal
parts with micro-scale features", Proc. 9th Solid Freeform
Fabrication, The University of Texas at Austin, p 161, Aug. 1998.
[0005] (2) A. Cohen, G. Zhang, F. Tseng, F. Mansfeld, U. Frodis and
P. Will, "EFAB: Rapid, Low-Cost Desktop Micromachining of High
Aspect Ratio True 3-D MEMS", Proc. 12th IEEE Micro Electro
Mechanical Systems Workshop, IEEE, p 244, January 1999. [0006] (3)
A. Cohen, "3-D Micromachining by Electrochemical Fabrication",
Micromachine Devices, March 1999. [0007] (4) G. Zhang, A. Cohen, U.
Frodis, F. Tseng, F. Mansfeld, and P. Will, "EFAB: Rapid Desktop
Manufacturing of True 3-D Microstructures", Proc. 2nd International
Conference on Integrated MicroNanotechnology for Space
Applications, The Aerospace Co., April 1999. [0008] (5) F. Tseng,
U. Frodis, G. Zhang, A. Cohen, F. Mansfeld, and P. Will, "EFAB:
High Aspect Ratio, Arbitrary 3-D Metal Microstructures using a
Low-Cost Automated Batch Process", 3rd International Workshop on
High Aspect Ratio MicroStructure Technology (HARMST'99), June 1999.
[0009] (6) A. Cohen, U. Frodis, F. Tseng, G. Zhang, F. Mansfeld,
and P. Will, "EFAB: Low-Cost, Automated Electrochemical Batch
Fabrication of Arbitrary 3-D Microstructures", Micromachining and
Microfabrication Process Technology, SPIE 1999 Symposium on
Micromachining and Microfabrication, September 1999. [0010] (7) F.
Tseng, G. Zhang, U. Frodis, A. Cohen, F. Mansfeld, and P. Will,
"EFAB: High Aspect Ratio, Arbitrary 3-D Metal Microstructures using
a Low-Cost Automated Batch Process", MEMS Symposium, ASME 1999
International Mechanical Engineering Congress and Exposition,
November, 1999. [0011] (8) A. Cohen, "Electrochemical Fabrication
(EFABTM)", Chapter 19 of The MEMS Handbook, edited by Mohamed
Gad-El-Hak, CRC Press, 2002. [0012] (9) "Microfabrication--Rapid
Prototyping's Killer Application", pages 1-5 of the Rapid
Prototyping Report, CAD/CAM Publishing, Inc., June 1999.
[0013] The disclosures of these nine publications are hereby
incorporated herein by reference as if set forth in full
herein.
[0014] The electrochemical deposition process may be carried out in
a number of different ways as set forth in the above patent and
publications. In one form, this process involves the execution of
three separate operations during the formation of each layer of the
structure that is to be formed: [0015] 1. Selectively depositing at
least one material by electrodeposition upon one or more desired
regions of a substrate. [0016] 2. Then, blanket depositing at least
one additional material by electrodeposition so that the additional
deposit covers both the regions that were previously selectively
deposited onto, and the regions of the substrate that did not
receive any previously applied selective depositions. [0017] 3.
Finally, planarizing the materials deposited during the first and
second operations to produce a smoothed surface of a first layer of
desired thickness having at least one region containing the at
least one material and at least one region containing at least the
one additional material.
[0018] After formation of the first layer, one or more additional
layers may be formed adjacent to the immediately preceding layer
and adhered to the smoothed surface of that preceding layer. These
additional layers are formed by repeating the first through third
operations one or more times wherein the formation of each
subsequent layer treats the previously formed layers and the
initial substrate as a new and thickening substrate.
[0019] Once the formation of all layers has been completed, at
least a portion of at least one of the materials deposited is
generally removed by an etching process to expose or release the
three-dimensional structure that was intended to be formed.
[0020] The preferred method of performing the selective
electrodeposition involved in the first operation is by conformable
contact mask plating. In this type of plating, one or more
conformable contact (CC) masks are first formed. The CC masks
include a support structure onto which a patterned conformable
dielectric material is adhered or formed. The conformable material
for each mask is shaped in accordance with a particular
cross-section of material to be plated. At least one CC mask is
needed for each unique cross-sectional pattern that is to be
plated.
[0021] The support for a CC mask is typically a plate-like
structure formed of a metal that is to be selectively electroplated
and from which material to be plated will be dissolved. In this
typical approach, the support will act as an anode in an
electroplating process. In an alternative approach, the support may
instead be a porous or otherwise perforated material through which
deposition material will pass during an electroplating operation on
its way from a distal anode to a deposition surface. In either
approach, it is possible for CC masks to share a common support,
i.e. the patterns of conformable dielectric material for plating
multiple layers of material may be located in different areas of a
single support structure. When a single support structure contains
multiple plating patterns, the entire structure is referred to as
the CC mask while the individual plating masks may be referred to
as "submasks". In the present application such a distinction will
be made only when relevant to a specific point being made.
[0022] In preparation for performing the selective deposition of
the first operation, the conformable portion of the CC mask is
placed in registration with and pressed against a selected portion
of the substrate (or onto a previously formed layer or onto a
previously deposited portion of a layer) on which deposition is to
occur. The pressing together of the CC mask and substrate occur in
such a way that all openings, in the conformable portions of the CC
mask contain plating solution. The conformable material of the CC
mask that contacts the substrate acts as a barrier to
electrodeposition while the openings in the CC mask that are filled
with electroplating solution act as pathways for transferring
material from an anode (e.g. the CC mask support) to the
non-contacted portions of the substrate (which act as a cathode
during the plating operation) when an appropriate potential and/or
current are supplied.
[0023] An example of a CC mask and CC mask plating are shown in
FIGS. 1A-1C. FIG. 1A shows a side view of a CC mask 8 consisting of
a conformable or deformable (e.g. elastomeric) insulator 10
patterned on an anode 12. The anode has two functions. FIG. 1A also
depicts a substrate 6 separated from mask 8. One is as a supporting
material for the patterned insulator 10 to maintain its integrity
and alignment since the pattern may be topologically complex (e.g.,
involving isolated "islands" of insulator material). The other
function is as an anode for the electroplating operation. CC mask
plating selectively deposits material 22 onto a substrate 6 by
simply pressing the insulator against the substrate then
electrodepositing material through apertures 26a and 26b in the
insulator as shown in FIG. 1B. After deposition, the CC mask is
separated, preferably non-destructively, from the substrate 6 as
shown in FIG. 1C. The CC mask plating process is distinct from a
"through-mask" plating process in that in a through-mask plating
process the separation of the masking material from the substrate
would occur destructively. As with through-mask plating, CC mask
plating deposits material selectively and simultaneously over the
entire layer. The plated region may consist of one or more isolated
plating regions where these isolated plating regions may belong to
a single structure that is being formed or may belong to multiple
structures that are being formed simultaneously. In CC mask plating
as individual masks are not intentionally destroyed in the removal
process, they may be usable in multiple plating operations.
[0024] Another example of a CC mask and CC mask plating is shown in
FIGS. 1D-1F. FIG. 1D shows an anode 12' separated from a mask 8'
that includes a patterned conformable material 10' and a support
structure 20. FIG. 1D also depicts substrate 6 separated from the
mask 8'. FIG. 1E illustrates the mask 8' being brought into contact
with the substrate 6. FIG. 1F illustrates the deposit 22' that
results from conducting a current from the anode 12' to the
substrate 6. FIG. 1G illustrates the deposit 22' on substrate 6
after separation from mask 8'. In this example, an appropriate
electrolyte is located between the substrate 6 and the anode 12'
and a current of ions coming from one or both of the solution and
the anode are conducted through the opening in the mask to the
substrate where material is deposited. This type of mask may be
referred to as an anodeless INSTANT MASK.TM. (AIM) or as an
anodeless conformable contact (ACC) mask.
[0025] Unlike through-mask plating, CC mask plating allows CC masks
to be formed completely separate from the fabrication of the
substrate on which plating is to occur (e.g. separate from a
three-dimensional (3D) structure that is being formed). CC masks
may be formed in a variety of ways, for example, a
photolithographic process may be used. All masks can be generated
simultaneously, prior to structure fabrication rather than during
it. This separation makes possible a simple, low-cost, automated,
self-contained, and internally-clean "desktop factory" that can be
installed almost anywhere to fabricate 3D structures, leaving any
required clean room processes, such as photolithography to be
performed by service bureaus or the like.
[0026] An example of the electrochemical fabrication process
discussed above is illustrated in FIGS. 2A-2F. These figures show
that the process involves deposition of a first material 2 which is
a sacrificial material and a second material 4 which is a
structural material. The CC mask 8, in this example, includes a
patterned conformable material (e.g. an elastomeric dielectric
material) 10 and a support 12 which is made from deposition
material 2. The conformal portion of the CC mask is pressed against
substrate 6 with a plating solution 14 located within the openings
16 in the conformable material 10. An electric current, from power
supply 18, is then passed through the plating solution 14 via (a)
support 12 which doubles as an anode and (b) substrate 6 which
doubles as a cathode. FIG. 2A, illustrates that the passing of
current causes material 2 within the plating solution and material
2 from the anode 12 to be selectively transferred to and plated on
the cathode 6. After electroplating the first deposition material 2
onto the substrate 6 using CC mask 8, the CC mask 8 is removed as
shown in FIG. 2B. FIG. 2C depicts the second deposition material 4
as having been blanket-deposited (i.e. non-selectively deposited)
over the previously deposited first deposition material 2 as well
as over the other portions of the substrate 6. The blanket
deposition occurs by electroplating from an anode (not shown),
composed of the second material, through an appropriate plating
solution (not shown), and to the cathode/substrate 6. The entire
two-material layer is then planarized to achieve precise thickness
and flatness as shown in FIG. 2D. After repetition of this process
for all layers, the multi-layer structure 20 formed of the second
material 4 (i.e. structural material) is embedded in first material
2 (i.e. sacrificial material) as shown in FIG. 2E. The embedded
structure is etched to yield the desired device, i.e. structure 20,
as shown in FIG. 2F.
[0027] Various components of an exemplary manual electrochemical
fabrication system 32 are shown in FIGS. 3A-3C. The system 32
consists of several subsystems 34, 36, 38, and 40. The substrate
holding subsystem 34 is depicted in the upper portions of each of
FIGS. 3A to 3C and includes several components: (1) a carrier 48,
(2) a metal substrate 6 onto which the layers are deposited, and
(3) a linear slide 42 capable of moving the substrate 6 up and down
relative to the carrier 48 in response to drive force from actuator
44. Subsystem 34 also includes an indicator 46 for measuring
differences in vertical position of the substrate which may be used
in setting or determining layer thicknesses and/or deposition
thicknesses. The subsystem 34 further includes feet 68 for carrier
48 which can be precisely mounted on subsystem 36.
[0028] The CC mask subsystem 36 shown in the lower portion of FIG.
3A includes several components: (1) a CC mask 8 that is actually
made up of a number of CC masks (i.e. submasks) that share a common
support/anode 12, (2) precision X-stage 54, (3) precision Y-stage
56, (4) frame 72 on which the feet 68 of subsystem 34 can mount,
and (5) a tank 58 for containing the electrolyte 16. Subsystems 34
and 36 also include appropriate electrical connections (not shown)
for connecting to an appropriate power source for driving the CC
masking process.
[0029] The blanket deposition subsystem 38 is shown in the lower
portion of FIG. 3B and includes several components: (1) an anode
62, (2) an electrolyte tank 64 for holding plating solution 66, and
(3) frame 74 on which the feet 68 of subsystem 34 may sit.
Subsystem 38 also includes appropriate electrical connections (not
shown) for connecting the anode to an appropriate power supply for
driving the blanket deposition process.
[0030] The planarization subsystem 40 is shown in the lower portion
of FIG. 3C and includes a lapping plate 52 and associated motion
and control systems (not shown) for planarizing the
depositions.
[0031] In addition to the above teachings, the '630 patent
indicates that electroplating methods can be used in combination
with insulating materials. In particular it indicates that though
the electroplating embodiments described therein have been
described with respect to the use of two metals, a variety of
materials, e.g., polymers, ceramics and semiconductor materials,
and any number of metals can be deposited either by the
electroplating methods described above, or in separate processes
that occur throughout the electroplating method. It indicates that
a thin plating base can be deposited, e.g., by sputtering, over a
deposit that is insufficiently conductive (e.g., an insulating
layer) so as to enable subsequent electroplating. It also indicates
that multiple support materials (i.e. sacrificial materials) can be
included in the electroplated element allowing selective removal of
the support materials.
[0032] Another method for forming microstructures from
electroplated metals (i.e. using electrochemical fabrication
techniques) is taught in U.S. Pat. No. 5,190,637 to Henry Guckel,
entitled "Formation of Microstructures by Multiple Level Deep X-ray
Lithography with Sacrificial Metal layers". This patent teaches the
formation of metal structure utilizing mask exposures. A first
layer of a primary metal is electroplated onto an exposed plating
base to fill a void in a photoresist, the photoresist is then
removed and a secondary metal is electroplated over the first layer
and over the plating base. The exposed surface of the secondary
metal is then machined down to a height which exposes the first
metal to produce a flat uniform surface extending across the both
the primary and secondary metals. Formation of a second layer may
then begin by applying a photoresist layer over the first layer and
then repeating the process used to produce the first layer. The
process is then repeated until the entire structure is formed and
the secondary metal is removed by etching. The photoresist is
formed over the plating base or previous layer by casting and the
voids in the photoresist are formed by exposure of the photoresist
through a patterned mask via X-rays or UV radiation.
[0033] A need still exists in the field for enhancing the
combinability of conducting materials, dielectric materials,
semi-conducting materials, other materials, processed materials,
and/or configured materials within the EFAB process. Furthermore, a
need exists in the field for combining electrochemically fabricated
structures with dielectric bases or substrates, active bases or
substrates (bases or substrates having elements that interact with
the structure or that serve a purpose other than merely as a mount
for the structure), and/or bases or substrates containing contoured
structures. A need remains in the field for improved adhesion
between bases or substrates and electrochemically fabricated
structures. A need remains in the field for extending the range of
capabilities, for expanding the range of materials, and processes
available for forming desired structures (including their bases or
substrates).
SUMMARY OF THE INVENTION
[0034] It is an object of various aspects of the present invention
to supplement electrochemical fabrication techniques to expand the
capabilities of electrochemical fabrication process to meet the
structural and functional requirements for varying applications and
thus to expand the potential applications available to the
technology.
[0035] Other objects and advantages of various aspects of the
invention will be apparent to those of skill in the art upon review
of the teachings herein. The various aspects of the invention, set
forth explicitly herein or otherwise ascertained from the teachings
herein, may address any one of the above objects alone or in
combination, or alternatively may not address any of the objects
set forth above but instead address some other object ascertained
from the teachings herein. It is not intended that all of these
objects be addressed by any single aspect of the invention even
though that may be the case with regard to some aspects.
[0036] A first aspect of the invention provides an electrochemical
fabrication process for producing a three-dimensional structure
from a plurality of adhered layers, the process including: (A)
selectively depositing at least a portion of a layer onto a
temporary substrate, wherein the temporary substrate may include
previously deposited material; (B) forming a plurality of layers
such that successive layers are formed adjacent to and adhered to
previously deposited layers, wherein said forming includes
repeating operation (A) a plurality of times; (C) after formation
of a plurality of layers, attaching a structural substrate
including a dielectric material to at least a portion of a layer of
the structure and removing at least a portion of the temporary
substrate from the structure.
[0037] A second aspect of the invention provides an electrochemical
fabrication apparatus for producing a three-dimensional structure
from a plurality of adhered layers, the apparatus including: (A)
means for selectively depositing at least a portion of a layer onto
a temporary substrate, wherein the temporary substrate may include
previously deposited material; and (B) means for forming a
plurality of layers such that successive layers are formed adjacent
to and adhered to previously deposited layers, wherein said forming
includes repeating operation (A) a plurality of times; (C) means
for attaching a structural substrate including a dielectric
material to at least a portion of a layer of the structure and
removing at least a portion of the temporary substrate from the
structure; and (D) a computer programmed to control the means for
contacting, the means for conducting, the means for separating, and
the means for attaching, such that the means for attaching is made
to operate after formation of a plurality of layers of the
structure.
[0038] A third aspect of the invention provides an electrochemical
fabrication process for producing a three-dimensional structure
from a plurality of adhered layers, the process including: (A)
selectively depositing at least a portion of a layer onto a first
temporary substrate, wherein the first temporary substrate may
include previously deposited material; and (B) forming a plurality
of layers such that successive layers are formed adjacent to and
adhered to previously deposited layers; and (C) after formation of
a plurality of layers attaching a second temporary substrate, which
includes a dielectric material, to at least a portion of a layer of
the structure and removing at least a portion of the first
temporary substrate from the structure and then attaching a
structural substrate to at least a portion of a layer of the
structure that at least partially overlaps a location where the
first temporary substrate was attached.
[0039] A fourth aspect of the invention provides an electrochemical
fabrication process for producing a three-dimensional structure
from a plurality of adhered layers, the process including: (A)
selectively depositing at least a portion of a layer onto a
sacrificial substrate, wherein the temporary substrate may include
previously deposited material; (B) forming a plurality of layers
such that each successive layer is formed adjacent to and adhered
to a previously deposited layer, wherein said forming includes
repeating operation (A) a plurality of times; (C) after formation
of a plurality of layers attaching a structural substrate,
including a plurality of materials and/or a patterned structure, to
at least a portion of a layer of the structure and removing at
least a portion of the temporary substrate from the structure.
[0040] A fifth aspect of the invention provides an electrochemical
fabrication process for producing a three-dimensional structure
from a plurality of adhered layers, the process including: (A)
selectively depositing at least a portion of a layer onto a first
temporary substrate, wherein the first temporary substrate may
include previously deposited material; and (B) forming a plurality
of layers such that successive layers are formed adjacent to and
adhered to previously deposited layers; and (C) after formation of
a plurality of layers attaching a second temporary substrate, which
includes a plurality of materials and/or includes a patterned
structure, to at least a portion of a layer of the structure and
removing at least a portion of the first temporary substrate from
the structure and then attaching a structural substrate to at least
a portion of a layer of the structure that at least partially
overlaps a location where the first temporary substrate was
attached.
[0041] A sixth aspect of the invention provides an electrochemical
fabrication process for producing a multi-part three-dimensional
structure wherein at least one part is produced from a plurality of
adhered layers, the process including: (A) forming at least one
part of the multi-part structure, including: (1) selectively
depositing at least a portion of a layer onto a substrate, wherein
the substrate may include previously deposited material; (2)
forming a plurality of layers such that successive layers are
formed adjacent to and adhered to previously deposited layers,
wherein said forming includes repeating operation (1) a plurality
of times; (B) supplying at least one additional part of the
multi-part structure; (C) attaching the at least one part to the at
least one additional part to form the multi-part structure.
[0042] Further aspects of the invention will be understood by those
of skill in the art upon reviewing the teachings herein. Other
aspects of the invention may involve combinations of the above
noted aspects of the invention and/or addition of various features
of one or more embodiments. Other aspects of the invention may
involve apparatus that is configured to implement one or more of
the above method aspects of the invention. These other aspects of
the invention may provide various combinations of the aspects
presented above as well as provide other configurations,
structures, functional relationships, and processes that have not
been specifically set forth above.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIGS. 1A-1C schematically depict side views of various
stages of a CC mask plating process, while FIGS. 1D-1G
schematically depict a side views of various stages of a CC mask
plating process using a different type of CC mask.
[0044] FIGS. 2A-2F schematically depict side views of various
stages of an electrochemical fabrication process as applied to the
formation of a particular structure where a sacrificial material is
selectively deposited while a structural material is blanket
deposited.
[0045] FIGS. 3A-3C schematically depict side views of various
example subassemblies that may be used in manually implementing the
electrochemical fabrication method depicted in FIGS. 2A-2F.
[0046] FIGS. 4A-4I schematically depict the formation of a first
layer of a structure using adhered mask plating where the blanket
deposition of a second material overlays both the openings between
deposition locations of a first material and the first material
itself.
[0047] FIG. 5 depicts a flow chart of the basic operations of a
preferred embodiment of the invention.
[0048] FIGS. 6A-6C depict an example of a structure created
according to a preferred embodiment of the invention where FIGS. 6A
and 6B depict two different perspective views of the structure
while FIG. 6C depicts a side view of the structure of FIGS. 6A and
6B.
[0049] FIGS. 7A-7O illustrate the production of the structure of
FIGS. 6A-6C from a plurality of adhered layers according to a
preferred embodiment of the invention.
[0050] FIG. 8A-8D illustrate a variation to the formation of the
last layer of the structure of FIGS. 6A-6C and how the permanent
substrate mates with that layer.
[0051] FIGS. 9A-9E depict the results of various steps during the
practice of an embodiment of the invention.
[0052] FIG. 10 provides a flowchart illustrating the basic
operations of the embodiment exemplified in FIGS. 9A-9E.
[0053] FIGS. 11A-11J depict the results of various operations
performed during the practice of an embodiment of the
invention.
[0054] FIG. 12 provides a flowchart illustrating basic operations
of another embodiment of the invention.
[0055] FIGS. 13A-13C schematically depict a process for swapping a
structure 702 from a first substrate 704 to a second substrate
706.
[0056] FIGS. 13D and 13E schematically depict side views of
structures and substrates having modified configurations for
enhancing attachment.
[0057] FIGS. 14A-14C schematically depict a process for modifying a
configuration of an attachment layer of a structure to include
notches as indicated in FIG. 13D.
[0058] FIG. 15A-15F schematically depict a process for modifying a
configuration of an attachment layer of a structure to include
reentrant features for enhancing interlocking of the structure and
the substrate.
DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION
[0059] FIGS. 1A-1G, 2A-2F, and 3A-3C illustrate various features of
one form of electrochemical fabrication that are known. Other
electrochemical fabrication techniques are set forth in the '630
patent referenced above, in the various previously incorporated
publications, in various other patents and patent applications
incorporated herein by reference, still others may be derived from
combinations of various approaches described in these publications,
patents, and applications, or are otherwise known or ascertainable
by those of skill in the art from the teachings set forth herein.
All of these techniques may be combined with those of the various
embodiments of various aspects of the invention explicitly set
forth herein to yield enhanced embodiments. Still other embodiments
be may derived from combinations of the various embodiments
explicitly set forth herein.
[0060] FIGS. 4A-4I illustrate various stages in the formation of a
single layer of a multi-layer fabrication process where a second
metal is deposited on a first metal as well as in openings in the
first metal where its deposition forms part of the layer. In FIG.
4A, a side view of a substrate 82 is shown, onto which patternable
photoresist 84 is cast as shown in FIG. 4B. In FIG. 4C, a pattern
of resist is shown that results from the curing, exposing, and
developing of the resist. The patterning of the photoresist 84
results in openings or apertures 92(a)-92(c) extending from a
surface 86 of the photoresist through the thickness of the
photoresist to surface 88 of the substrate 82. In FIG. 4D, a metal
94 (e.g. nickel) is shown as having been electroplated into the
openings 92(a)-92(c). In FIG. 4E, the photoresist has been removed
(i.e. chemically stripped) from the substrate to expose regions of
the substrate 82 which are not covered with the first metal 94. In
FIG. 4F, a second metal 96 (e.g., silver) is shown as having been
blanket electroplated over the entire exposed portions of the
substrate 82 (which is conductive) and over the first metal 94
(which is also conductive). FIG. 4G depicts the completed first
layer of the structure which has resulted from the planarization of
the first and second metals down to a height that exposes the first
metal and sets a thickness for the first layer. In FIG. 4H the
result of repeating the process steps shown in FIGS. 4B-4G several
times to form a multi-layer structure are shown where each layer
consists of two materials. For most applications, one of these
materials is removed as shown in FIG. 4I to yield a desired 3-D
structure 98 (e.g. component or device).
[0061] Though the embodiments discussed herein are primarily
focused on conformable contact masks and masking operations, the
various embodiments, alternatives, and techniques disclosed herein
may have application to proximity masks and masking operations
(i.e. operations that use masks that at least partially selectively
shield a substrate by their proximity to the substrate even if
contact is not made), non-conformable masks and masking operations
(i.e. masks and operations based on masks whose contact surfaces
are not significantly conformable), and adhered masks and masking
operations (masks and operations that use masks that are adhered to
a substrate onto which selective deposition or etching is to occur
as opposed to only being contacted to it).
[0062] FIG. 5 presents the basic operations of a preferred
embodiment of the invention in the form of a flowchart. The process
starts with operation 102 which calls for supplying a substrate
onto which successive layers of deposited material will be added.
This substrate is typically made from a conductive material onto
which electrodeposition can occur but may be a dielectric material
onto which a seed layer of conductive material has been
deposited.
[0063] The process continues with operation 104 which calls for the
deposition of a layer onto the substrate or onto a previously
formed layer that is already on the substrate. The layer deposited,
according to certain embodiments of the invention will contain two
or more materials one or more of which are patterned to have a
desired configuration for the structure being formed and the other
one or more materials acting as sacrificial material which will be
removed from the structure after layer formation is completed. As
preferred embodiments of the invention call for the separation of
the structure from the substrate on which it was formed (i.e. the
temporary substrate), and as it may be desirable for the substrate
to be made from a structural material as opposed to a sacrificial
material, in certain embodiments, the first one or more layers
deposited on the substrate may be comprised solely of sacrificial
material.
[0064] Furthermore, in preferred embodiments of the present
invention, as the substrate on which structure is formed is not the
permanent substrate on which the structure will reside, it is
preferred in some embodiments for the first layers deposited (of
the structure) to be the last layers of the structure relative to
the permanent substrate and the last layers deposited to be the
first layers relative to the permanent substrate. In other words,
in some embodiments it is desirable for the structure's layers to
be deposited in reverse order.
[0065] The electrochemical fabrication process used may be similar
to the one illustrated in FIGS. 1A-1C and 2A-2F or it may be
another process set forth in the '630 patent, a process set forth
in one of the other previously incorporated publications, a process
described in one of the patents or applications that is included in
the table of incorporated patents and applications set forth
hereafter, or the process may be a combination of various
approaches described in these publications, patents, and
applications, or the process may be otherwise known or
ascertainable by those of skill in the art. Of course portions of
the structures may be formed by other three-dimensional modeling or
fabrication processes.
[0066] After deposition of a layer, the process proceeds to
operation 106 in which an inquiry is made as to whether the last
layer of the structure has been formed (i.e. the layer that will
contact the permanent substrate in certain embodiments of the
invention). If the answer is "no", the process loops back to
operation 104 for further depositions. If the answer is "yes", the
process moves forward to operation 108.
[0067] Operation 108 calls for the attachment of a permanent
substrate (e.g. a dielectric material) to the last deposited layer
of the structure. The attachment may occur via an adhesive (e.g. a
pressure sensitive adhesive, a heat sensitive adhesive, or a
radiation curable adhesive (if the substrate is transmissive of the
appropriate radiation). The application of the adhesive may occur
in various ways known to those of skill in the art (e.g. spreading,
spinning, spraying, and the like). Attachment may alternatively
occur via non-adhesive based bonding techniques, e.g. surface
melting, sintering, brazing, ultrasonic welding, vibration welding,
and the like.
[0068] After attaching the permanent substrate and the layers of
deposited material together, the process proceeds to operation 110
where a permanent substrate and layers are separated from the
temporary substrate and any sacrificial material is removed. The
separation process may occur as a natural part of the sacrificial
material removal process if one or more layers of sacrificial
material are interposed between the temporary substrate and the
structural material or if the temporary substrate is made of the
sacrificial material or other material that is attacked by an
etchant being used to selectively separate the sacrificial and
structural materials.
[0069] In alternative embodiments, the three tasks set forth in
operations 108 and 110 may be performed in varying orders, for
example: (1) bonding and then simultaneous separation and removal
of sacrificial material, (2) bonding, separation, then removal, (3)
simultaneous separation and removal then bonding, (4) removal,
bonding, then separation.
[0070] FIGS. 6A-6C depict an example of a structure (e.g. a switch)
created according to a preferred embodiment of the invention. Two
different perspective views of the structure are shown in FIGS. 6A
and 6B and a side view is shown in FIG. 6C. The view seen in FIG.
6A allows the structure 122 to be seen in its entirety while the
structure is attached to permanent substrate 124. The view seen in
FIG. 6B obscures a portion of structure 122 when it is attached to
permanent substrate 124 but allows the layer formation process to
be seen when the structure is being formed and attached to the
temporary substrate as shown in FIGS. 7A to 7N. As can be seen in
FIG. 6C the structure consists of ten layers numbered 201-210.
[0071] FIGS. 7A-7O illustrate various states of the process
associated with the formation of the structure of FIGS. 6A-6C. In
this embodiment, successive layers are formed and adhered to the
bottom of previously deposited layers. With the exception of the
sacrificial material shown in FIG. 7B, when showing structural
material and sacrificial material on the current deposition layer,
the structural material is fully illustrated while only an outline
of the sacrificial material is shown. On a current deposition layer
any order of depositing structural material and sacrificial
material is acceptable. In alternative embodiments, the layers may
be deposited one on top of the other or one beside the other. In
this application, unless a different interpretation is required by
the context, when a deposition is said to occur onto a previous
deposition, no absolute inference of layer orientation should be
made but only a relative orientation of deposition order should be
inferred.
[0072] FIG. 7A illustrates that the process starts with a temporary
substrate 212.
[0073] FIG. 7B indicates that the temporary substrate is supplied
with a coating or first deposited layer 211 of sacrificial
material. This layer 211 of sacrificial material will allow
separation of the structural material from the temporary substrate
during a later step of the formation process. Of course in actual
practice, more than one such layer 211 may be formed or its
thickness may be tailored to allow easy separation during a later
step.
[0074] FIG. 7C shows the structural material 210' of layer 210 that
is patterned along with a dashed outline indicating the boundary of
the sacrificial material that is also present.
[0075] FIGS. 7D-7L increment through successive deposition layers
ranging from layer 209 down to 201. The pattern of structural
material 209' to 201' for each of the current deposition layers is
also shown along with an outline of the sacrificial material
associated with the current layer. Previously deposited layers are
shown as solid blocks of material without distinction between the
patterning of the structural and sacrificial materials.
[0076] FIGS. 7M and 7N depict the attachment of the permanent
substrate 200 to (1) the stack of layers 201-210, (2) the release
layer 211, and (3) the temporary substrate 212. FIG. 7M depicts the
various elements of the partially formed structures as solid
blocks, while FIG. 7N depicts the sacrificial material and
permanent substrate as transparent so that the layers and
configuration of the structural material 201'-210' may be seen.
[0077] FIG. 7O depicts the released structural material 201'-210'
adhered to the permanent substrate 200. The substrate is shown as
transparent for illustrative purposes but which may be opaque or
transparent (e.g. glass) wherein some applications may require or
benefit from such a material (e.g. when the structure includes a
scanning mirror that is to receive radiation through the substrate
and transmit it back out through the substrate). The temporary
substrate may be removed along with the sacrificial material which
may be removed by selective etching with an etchant (e.g. Enstrip
C-38) that is selective to the sacrificial material (e.g. copper)
but non-destructive to the structural material (e.g. nickel). The
sacrificial material etchant may include an anti-pitting agent, or
the like, to help ensure that it does not attack the structural
material.
[0078] FIGS. 8A-8D illustrate a variation to the formation of the
last layer of the structure of FIGS. 6A-6C and a variation in how
the permanent substrate mates with that layer. FIG. 8A shows the
final layer including only the structural material 201'. FIG. 8B
depicts the permanent substrate being formed or adhered to not only
the bottom of the last layer but also to the sides of the last
layer such that the structural material of the last layer becomes
at least partially embedded in the substrate. FIGS. 8C and 8D
depict two perspective views of the resulting structure. As can be
seen, structural material 201' is embedded in the substrate and
only nine of the ten original layers of structural material extend
above the surface of the permanent substrate. The surrounding of
the structural material 201' by the substrate may be achieved in
various ways. For example, instead of the substrate being in the
form of a performed sheet that is bonded to the layers, it may be
in the form of a flowable material that can be molded to partially
embed the structural material and to have a desired thickness
extending beyond the surface of the last layer of structural
material. As another example, the substrate may still be in the
form of a sheet that is bonded to the structural material 201' of
the last layer but a portion of the last layer where the
sacrificial material has been removed or never deposited may be
filled with an epoxy or other flowable/solidifiable material. The
permanent substrate may be placed in position and the hardening of
the epoxy or other material may not only fill the region around
structural material 201' but also cause bonding between the layers
and the substrate.
[0079] Various alternatives to the above embodiments exist. Even
when not molding the substrate around, the sides of at least one
layer, it is still possible to use a moldable material and form the
substrate from a temporarily flowable material as opposed to a
sheet of material. Contact pads and runners may be formed of the
structural material and these may extend to desired locations on
the surface of the substrate or may even be encapsulated by the
substrate material except at desired contact points. A selective
partial etching of the sacrificial material may occur before
attachment or formation of the permanent substrate. Layers of
material may be etched to a depth of less than one layer thickness
or more than one layer thickness. In some embodiments, the depth of
etching may be such that portions of the structural material may
extend completely through the substrate that will be molded so as
to form interconnects that protrude from the bottom of the
substrate. In embodiments where it is desired to have interconnects
extend through the bottom of the substrate, and when such extension
does not occur during molding, the back side of the substrate may
be planarized until the structural material is exposed. Substrates
need not be planar and their lateral extents need not correspond to
those of the layers.
[0080] If partially etching to a depth of more that one layer
thickness, it is preferred that the pattern of structural material
remain of fixed pattern, for all but maybe the deepest layer that
will be exposed by the partial etching. This will help ensure a
more uniform depth of etching since the sacrificial material will
not be shielded by regions of extended structural material.
However, in embodiments where the depth of etching is less critical
or it is determined that a varying structural pattern will yield a
desired etching pattern, no such restriction on structural material
patterning need exist.
[0081] In some embodiments instead of the temporary substrate and
permanent substrate being mounted on opposite sides of the
deposited layers, the permanent substrate may be mounted in an
orientation perpendicular to that of the temporary substrate. In
other words, the permanent substrate may be mounted to the sides of
a plurality of deposited layers.
[0082] In some embodiments, instead of attaching the permanent
substrate to the opposite side of the stack of layers relative to
the temporary substrate, the temporary substrate may be removed and
the permanent substrate bonded in its place. This may occur by
having the temporary substrate or its upper most surface formed of
a material that can be selectively etched or otherwise removed from
the layers of material preferably without damaging either the
structural material or sacrificial material of those layers. And
after removal, the bottom most layer of the structure would be
exposed and the permanent substrate (e.g. dielectric substrate)
attached thereto.
[0083] When desiring to mount the permanent substrate into the same
position occupied by the temporary substrate, in some embodiments
it may be desirable to first mount a second temporary substrate on
the opposite side of the stack as compared to the first temporary
substrate after which the first temporary substrate may be removed,
followed by attachment of the permanent substrate, and then
followed by the removal of the second temporary substrate. In still
other embodiments, the permanent substrate can be mounted on the
opposite side of the stack of layers as compared to the substrate
on which the layers were formed and the substrate on which the
layers were formed can remain.
[0084] In some embodiments of the invention, the permanent
substrate may not be a dielectric but instead may be of some other
material. For example, the permanent substrate might be made of a
conductive material that can not be readily electrodeposited.
[0085] Though the use of the term "permanent substrate" has been
used herein, it should be understood that it is not intended that
the permanent substrate must exist throughout the life of the
structure but instead that if form part of the structure for at
least some portion of its useful life.
[0086] In some embodiments of the invention, a sacrificial material
may not be used when depositing the layers one upon the other. In
some embodiments, formation of layers may be by single or multiple
selective depositions and potentially one or more blanket
depositions and potentially one or more planarization
operations.
[0087] Some embodiments of the invention may provide for attachment
of electrochemically produced structures (e.g. structures formed
using conformable contact masking techniques or adhered masking
techniques) to substrates that may include active elements. This is
illustrated in the embodiment of FIGS. 9A-9E where an
electrochemically fabricated structure is attached to a
piezoelectric element and the combination of the two provide a
working piezoelectric device.
[0088] In FIG. 9A, a structure 302 includes structural material 304
surrounded by a sacrificial material 306. The structure 302 is
preferably fabricated via electrochemical fabrication from a
plurality of adhered layers. The structure 302 is fabricated on a
release material 308 which in turn is attached to a substrate 312.
The release material 308 may be the same as the sacrificial
material 306 or alternatively it may be another material that can
be separated, e.g. by etching or melting (e.g., a solder) or
otherwise removed. The release material 308 may have been coated
onto a substrate 312 prior to the start of electrochemical
fabrication of the structure 302 or it may be formed as a result of
one or more initial depositions of the electrochemical fabrication
process. The substrate is typically a conductive material though in
some embodiments it may be dielectric material which may be coated
with a seed layer of conductive material.
[0089] In FIG. 9B, a pre-fabricated element or component 322 is
shown located above the structure 302. The pre-fabricated element
or component 322 has been prepared for attachment to the
electrochemically fabricated structure 302. The element or
component 322 is attached to a device substrate 324. Typically, the
device substrate 324 will serve as the final substrate for the
device which will be a combination of element or component 322 and
the structural material of structure 302. Depending the final
requirement of a particular device the device substrate may take on
any desired properties (e.g. be a conductor, a dielectric, a
transparent material, a flexible material, etc.). In the present
example the device substrate 324 is a dielectric so that it may
provide electrical isolation). On the device substrate a metal
element 326 is patterned, on to which a region of piezoelectric
material 328 is patterned, and on to which an adhesive 330 (which
may be electrically conductive if desired) is patterned. An
appropriate adhesive is one which provides good adhesion to the
structural material 304 of the structure 302. The metal element 326
is provided and patterned to serve as an electrode to actuate the
piezoelectric material and as a trace that interconnects the
electrode to a power supply.
[0090] In FIG. 9C, the pre-fabricated element or component 322 is
shown as being adhered to structure 302 by means of the adhesive
330. In FIG. 9D, the release material 308 is shown as being
removed. Finally, in FIG. 9E, the sacrificial material 306 has been
removed from structural material 304 to release component 334 from
structure 302 thereby yielding the completed device 336 which is a
combination of component 334, component 322, and device substrate
324.
[0091] FIG. 10 provides a flow chart illustrating the process flow
associated with the embodiment of FIGS. 9A-9E. In FIG. 10, the
process begins at two points as illustrated by blocks 402 and 406.
Block 402 calls for the supplying of a substrate that is separable
from a component that will be formed thereon. The substrate and
component might be separable as a result of the substrate having a
release layer thereon, or they might be separable as a result of a
release layer that will be formed on the substrate.
[0092] Block 406 calls for the supplying of a second component,
where the second component will have a desired shape or will be
composed of multiple desired materials. The second component will
have a surface that can be attached to the surface of the first
component as supplied in association with block 402.
[0093] Block 404 calls for the formation of one or more layers on
the substrate so as to form a first component (i.e. portion) of a
device that is to be created. In the process of forming the first
component, the component may be partially surrounded by a
sacrificial material which will be eventually removed from the
component portion of the layers that are formed. The first
component will have a surface that is capable of being bonded or
otherwise attached to the second component. Both blocks 404 and 406
are the starting points for the operation of block 208.
[0094] In block 408 either one or both of the first and second
components are prepared for adhesion to the other component by the
addition of an adhesive to at least one of the bonding surfaces. Of
course in alternative embodiments block 408 may not be part of the
process. In some embodiments, for example, an adhesive may be part
of the second component that is supplied.
[0095] From block 408 the process moves forward to block 410 where
the two components are bonded or otherwise attached to one another.
This attachment may occur by use of a pressure sensitive adhesive,
a hot melt adhesive, or by other means known to those of skill in
the art.
[0096] The process then moves forward to block 412 where the first
component is separated from the substrate on which it was
formed.
[0097] Then the process moves forward to block 414 where the first
component is separated from any sacrificial material that is not to
remain part of the final device that is being created.
[0098] Next the process moves to block 416 where either additional
manufacturing operations may be performed or where the device that
was released in the operation of block 414 may be put to use.
[0099] In alternative embodiments, the order of operations
associated with blocks 414 and 412 may be reversed. In still other
embodiments the accomplishment of the operations of blocks 414 and
412 may occur simultaneously. In still further alternative
embodiments either one of the operations of blocks 412 or 414 or
both of them may occur between the operations of blocks 408 and
410. Various other alternatives will be apparent to those of skill
of the art upon reviewing the teachings herein.
[0100] In some embodiments of the invention the attached substrate
may be a passive device but the structure that is attached to it
may include structures having electrochemically fabricated portions
and portions fabricated by other deposition or patterning
techniques. One or both the portions may include active components.
This is illustrated in the embodiment of FIGS. 11A-11J.
[0101] FIGS. 11A-11J illustrate another alternative embodiment of
the invention which includes formation of a number of layers using
similar operations followed by formation of additional portions of
a structure using alternative operations. FIG. 11A depicts a side
view of a first structure 502 which for illustrative purposes is
identical to that of FIG. 9A.
[0102] In FIG. 11B, a piezoelectric material 528 has been deposited
onto the top surface (i.e., last layer) of structure 502, and a
photoresist 520 has been deposited on to the piezoelectric material
528.
[0103] In FIG. 11C, a desired pattern of piezoelectric material 528
is shown. The patterning of this piezoelectric material may occur
by first patterning the photoresist 520 which is then used as a
pattern for selectively etching the piezoelectric material. In an
alternative process, for example, the piezoelectric material may
have been patterned by lift-off methods, and the like.
[0104] FIG. 11D illustrates an optional step for bringing the
surface level of the partially formed device to a uniform height by
using a dielectric material 532 to fill the voids that resulted
from the etching of the piezoelectric material. In some alternative
embodiments, it may be necessary, or at least desirable, to
planarize the combined dielectric and piezoelectric material
layer.
[0105] FIG. 11E, depicts the resulting structure after deposition
of a next layer that supplies a metal 534 on top of the
piezoelectric and dielectric materials.
[0106] FIG. 11F, illustrates the result of an operation that
patterns the deposited metal. The pattern of the metal is selected
to form an electrode for the piezoelectric element as well as an
interconnect trace. The patterning of the metal may occur in a
variety of ways, for example, it may occur in one of the ways noted
above for patterning the piezoelectric material. FIG. 11G
illustrates the result of an operation that fills the voids in the
metal layer with a dielectric material 536 which may be the same as
dielectric 532. The filling of the voids may be carried out in a
manner similar to that used for filling the voids in the
piezoelectric containing layer. For example, a material may be
deposited in bulk, distributed, cured, and then planarized to yield
a layer of desired thickness and uniformity. In FIG. 11H, a device
substrate 538 is illustrated as being applied over the
metal/dielectric layer. The substrate may have any desired
properties and in the present example it is a dielectric. In FIG.
11I, a release material 508 is shown as having been removed.
Finally, in FIG. 11J, a sacrificial material 508 is shown as having
been removed so as to yield a released device that may undergo
additional processing operations or be put to use.
[0107] In a final functional device, an electric connection through
the structural material 304 of FIG. 9E or 504 of FIG. 11J may be
used to provide a second electrode for the piezoelectric element in
order to produce a functional device.
[0108] FIG. 12 provides a flow chart illustrating the process
exemplified in FIGS. 11A-11J. The process starts with block 602
where a substrate is supplied onto which a device is to be formed.
Also as the device will be eventually transferred to a different
substrate the substrate should either have a release layer already
in place or alternatively an appropriate release material (e.g.
sacrificial material) may be added during the first one or more
layers of electrochemical fabrication.
[0109] Block 604 calls for the formation of one or more layers
(e.g. by Electrochemical Fabrication) using a first process which
will form a portion of the device which may be surrounded by a
sacrificial material.
[0110] Block 606 calls for the use of at least one different
deposition process to further build up and pattern the structure.
In some embodiments additional electrochemical fabrication
operations may be used in completing formation of the structure
which will include the unreleased device.
[0111] Block 608 calls for the placement of an adhesive on the last
layer of the formed structure and/or on a substrate that is going
to be bonded to the structure. The use of such adhesive may or may
not be necessary depending on the material that the substrate is
made from and the process or processes that will be used to cause
joining.
[0112] Block 610 calls for the formation of the substrate on the
last formed layer of the structure or the adherence on the
substrate to the last formed layer.
[0113] Block 612 calls for the separation of the structure from the
original substrate on which it was formed.
[0114] Block 614 calls for the separation of the structure from any
sacrificial material that is not to remain part of the final
device. This separation will result in a release of the device.
[0115] Block 616 calls for the performance of any additional
fabrication operations or the putting of the device into use. As
with the flowchart of FIG. 10, various alternative operations may
be performed as well as various reorderings of the blocks of the
exemplified operations.
[0116] Two additional embodiments are depicted in FIGS. 13A-13E,
14A-14C, and 15A-15F. These two additional embodiments depict
substrate swapping techniques that include either enhanced surface
area (interlacing) between the structure and the adhered substrate
or the formation of features in the structure that allow
interlocking with the swapped substrate.
[0117] FIGS. 13A-13C schematically depict a process for swapping a
structure 702 from a first substrate 704 to a second substrate 706
where the contact area between the structure and the second
substrate is substantially planar and thus no enhanced surface area
or interlocking regions exist to aid in improving adhesion.
[0118] FIG. 13D depicts a modified structure 702' and modified
substrate 706' where notches exist in what was a planar surface of
the structure and where protrusions in either the swapped substrate
or in an adhesive enter the notches and enhance adhesion between
the structure and substrate.
[0119] FIG. 13E depicts a modified structure 702'' adhered to a
modified swapped substrate 706'' where the structure includes
notches with undercuts in which material from the swapped substrate
or an adhesive becomes located such that adhesion between the
structure and substrate is enhanced by mechanical interlocking
between them.
[0120] The modified structure of FIG. 13D can be implemented via a
number of different processes. One implementation is depicted in
FIGS. 14A-14C.
[0121] FIG. 14A depicts the final two layers of the structure 712
and 714 as they would have been produced when no interlocking would
occur upon attachment of layer 714 to a substrate.
[0122] FIG. 14B depicts a modified version of layers 712 and 714'
where layer 714' is modified to include holes, notches, slots, or
the like in the structural material 718. These holes and notches
may be filled with a sacrificial material 720 as part of the layer
formation process. FIG. 14C depicts the state of the process after
the sacrificial material 720 shown in FIG. 14B is removed from the
openings 722 in layer 714'.
[0123] In some embodiments, the openings in layer 714' may have
occurred during the layer formation process as a result of
modifying the data descriptive of the layer. Alternatively, in
other embodiments the holes in layer 714' may have been made after
layer formation was completed by selectively etching holes into a
layer 714 at desired locations. Such etching processes may be
performed using contact masks or adhered masks. The etching out of
sacrificial material 720 on the other hand may occur in bulk if one
is not concerned about removing sacrificial material from other
regions of the structure. Or alternatively, the etching may occur
by use of one or more masks that at least shield regions of
sacrificial material that are not to be removed or that also shield
the structural material. After the openings are etched into the
layer which is to contribute to adhesion, an adhesive or flowable
substrate material may be applied and the substrate bonded to the
structure or solidified in contact with the structure (which
results in bonding).
[0124] In some embodiments, it is preferable that the sacrificial
material located in regions outside the structural material
portions of layer 714 not be etched away prior to occurrence of the
bonding operation. Such ordering of bonding and removal of
sacrificial material may allow for improved bonding orientation
between the substrate and the structure and/or may help limit the
movement of adhesive or flowable substrate material into regions
surrounding the structure. In other embodiments it maybe preferable
to remove the sacrificial material that is external to the
structural material regions, for example, as the sacrificial
material may be more accessible prior to bonding than after
bonding.
[0125] In still other embodiments, external region etching may
occur prior to bonding simply because the structures being bonded
are relatively tolerant to non-uniformities in orientation or exact
positioning and/or to the partial or complete filling of voids by
flowable substrate material or adhesive. The obtainment of data
associated with modifying the last layer of the structure (or even
the last several layers of a structure) may be based upon a
designer modifying a CAD file descriptive of the desired structure
or by a data processing program that performs various Boolean
operations (e.g. erosion or expansion operations) which may be
based on fixed or user definable sets of parameters (e.g. a fixed
grid of attachment locations and sizes which can be overlaid
against the exact position of the structural material of the layer
or layers). Such data processing operations may be based on
structural data that has already been transformed into layer data
or it may be based on structural data that remains in a
three-dimensional format.
[0126] The gripping functionality of the transition region between
the structure and the substrate of FIG. 13E may be obtainable in a
variety of ways. For example, an etching operation may be used that
has a tendency to undercut the material that it is cutting into.
Such undercutting may be the result of the compression of a
conformable contact mask into the hole as it is being formed which
may offer protection for the upper portions of the side walls of
the openings until a certain depth is reached at which point
horizontal etching may form an undercut. Such gripping
functionality may also be obtained by modifying the pattern of
structural material on the last two or more layers of structure
wherein the contacting layer (and maybe one or more additional
layers will have relatively small openings in the structural
material and one or more previous layers will have broader
openings. These smaller openings and wider openings on different
layers may be filled in with a sacrificial material during the
layer formation process. The sacrificial material can be removed
after layer formation is complete in much the same manner as
described with regard to FIGS. 14B and 14C. An example of the
formation of these gripping, undercut, or interlocking structures
is depicted in FIGS. 15A-15F.
[0127] FIG. 15A depicts the last five layers of a sample structure
formed by electrochemical fabrication wherein each of the five
layers has the same configuration. As indicated, the structure
includes regions of structural material 752 and regions of a
sacrificial material 754 which are external to the structure
itself.
[0128] FIG. 15B depicts the last several layers of a structure
formed by electrochemical fabrication where the configuration of
the last two layers has been modified to include openings in the
structural material that have undercuts or reentrant
configurations. As shown in FIG. 15B, reentrant structures 762 and
764 as well as channels 772 and 774 that lead to them are
temporarily filled with a second sacrificial material that may or
may not be the same as the first sacrificial material 754.
[0129] FIG. 15C depicts the pocket or reentrant structures 762 and
764 and associated channels 772 and 774 with the second sacrificial
material removed.
[0130] FIG. 15D depicts the structure after being coated with an
adhesive 774 and with a swapping substrate 776 located in position
for bonding.
[0131] FIG. 15E depicts the state of the process after the swapping
substrate 776 has been lowered into position and bonded to the
structure via adhesive 774. Not only has bonding occurred between
the substrate and the structure, interlocking has occurred between
the adhesive and the structure, and if the adhesive has better
bonding characteristics with the substrate than the structure then
the overall integrity of the combined substrate-structure system
has been improved.
[0132] FIG. 15F depicts the state of the process after the external
sacrificial material 754 has been removed.
[0133] Many alternatives to this interlocking approach as well as
the increased surface area approach are possible. In either
approach, the interlacing or interlocking elements may extend from
a fraction of a layer to multiple layers in height. Instead of
using an adhesive to bond the substrate and the structure together,
flowable substrate material may have been made to fill the openings
after which it would be allowed to solidify or otherwise be made to
solidify.
[0134] In other embodiments the substrate itself could include
openings or reentrant features which could assist in the gripping
of an adhesive or filler material to it. In still other embodiments
the reentrant features may not be such that any feature alone forms
a locking pattern between the substrate and the structure but where
a combination of two or more such structures result in a locking
configuration (e.g. straight holes extending into the structure at
different angles).
[0135] In still other embodiments, the two elements to be attached
may not include a multi-layer structure and a substrate, they may
instead include one or more multi-layer structures in combination
with one or more other elements or components that may or may not
be multi-layer structures, and may or may not be considered
substrate-like.
[0136] One embodiment for forming interlock enhanced bonded
structures may be summarized as follows: (1) obtain a file
descriptive of the structure to be formed; (2) modify the data so
as to include one or more branches or channels in the last one or
more layers and pockets or reentrant structures in one or more
layers that immediately proceed the layers that include the
channels; (3) form the structure on a first substrate; (4) etch out
the branches and pockets of the reentrant openings; (5) apply a
flowable material to the surface of the structure that has the
branches or channels where the applied flowable material may be an
adhesive if a separate substrate will be bonded by it or it may be
a solidifiable material that will be cast or otherwise made to take
the shape of a desired substrate; (6) bond the substrate and
structure using the adhesive or solidify the substrate material so
as to form a substrate that is bonded to the structure; and (7)
remove any other sacrificial material the remains and release the
first substrate from the structure if desired and if not previously
removed.
[0137] Many further alternative embodiments are possible and
additional examples include: (1) the use of a single sacrificial
material to fill the openings as well as the regions external to
the structure or to use more then two sacrificial materials; (2)
formation of the openings in the structural material in such a way
that a sacrificial material is not needed to temporarily fill the
openings; and/or (3) use of multiple structural materials. The
channels or branches leading to the pockets or reentrant features
may have any desired length, they may vary in cross-sectional
dimension or they may have variable lengths. The pockets or
reentrant features need not have a size difference from that of the
channels as they may simply be offset from the position of the
channels and in this regard they may actually have smaller
cross-sectional area; (5) there need not be a one to one
correspondence between pockets and channels; (6) the pockets
themselves may have different heights, be located at different
depths within the structure and or have different cross-sectional
dimensions.
[0138] In other alternative embodiments, instead of using undercuts
or reentrant features that penetrate into the interior of a
structural element, it may be possible to form undercuts on the
side walls of regions of structural material which undercuts may be
filled with a bonding or substrate material and may act as
interlocking elements when considered in association with
oppositely oriented undercuts on other portions of the structural
material.
[0139] In some embodiments, multi-layer structures may be formed
starting with a "top" layer (i.e. intended last layer) which is
formed adjacent to a temporary substrate, or possibly separated
from the temporary substrate by one or more layers of sacrificial
material and then adding on subsequent layers until the first layer
is reached. In these cases substrate swapping may occur directly by
attaching the structural (e.g. permanent substrate) to the last
formed layer (e.g. intended first layer) and then, if not already
done, the temporary substrate can be removed. In some other
embodiments, the multi layer structure can be formed starting with
the intended first layer which may be formed directly on a
temporary substrate or may be spaced from the temporary substrate
by a sacrificial material which may or may not be the same as the
sacrificial material that forms part of the layers including
structural material. The building may proceed from the first layer
to the last layer and if desired one or more layers of sacrificial
material may be formed above the last layer. The sacrificial
material above the last layer may or may not be the same as the
sacrificial material used in forming the layers that contain both
structural and sacrificial materials. If necessary, a second
temporary substrate may be attached to the last layer or the layers
above it. The first temporary substrate (i.e. the initial
substrate) may then be removed. If any layers of sacrificial
material exist below the first layer they may be removed and
thereafter a permanent (or structural substrate) may be attached to
the first layer, after which the second temporary substrate may be
removed along with any sacrificial material that has not yet been
removed.
[0140] In some embodiments, the structural substrates may be rigid
while in others they may be flexible. In still other embodiments,
the permanent substrates may be integrated circuits or other
electrical components to which attachment may be made by one or
more of dielectric adhesives, wire bonds, re-flowed solder
contacts, and/or other conductive or dielectric elements.
[0141] Many other alternative embodiments will be apparent to those
of skill in the art upon reviewing the teachings herein. Further
embodiments may be formed from a combination of the various
teachings explicitly set forth in the body of this application.
Even further embodiments may be formed by combining the teachings
set forth explicitly herein with teachings set forth in the
following patents and patent applications each of which is hereby
incorporated herein by reference:
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Monolithic Structures Including Alignment and/or Oct. 1, 2003
Retention Fixtures for Accepting Components Apr. 21, 2004 Cohen, et
al., Methods of Reducing Interlayer Discontinuities in
Electrochemically Fabricated Three-Dimensional Structures
10/841,300 Lockard, et al., Methods for Electrochemically
Fabricating May 7, 2004 Structures Using Adhered Masks,
Incorporating Dielectric Sheets, and/or Seed layers That Are
Partially Removed Via Planarization 10/271,574 Cohen, et al.,
Methods of and Apparatus for Making High Aspect Oct. 15, 2002 Ratio
Microelectromechanical Structures 20030127336 A1 Jul. 10, 2003
10/697,597 Lockard, et al., EFAB Methods and Apparatus Including
Spray Dec. 20, 2002 Metal or Powder Coating Processes 10/677,498
Cohen, et al., Multi-cell Masks and Methods and Apparatus for Oct.
1, 2003 Using Such Masks To Form Three-Dimensional Structures
10/724,513 Cohen, et al., Non-Conformable Masks and Methods and
Nov. 26, 2003 Apparatus for Forming Three-Dimensional Structures
10/607,931 Brown, et al., Miniature RF and Microwave Components and
Jun. 27, 2003 Methods for Fabricating Such Components, 10/841,100
Cohen, et al., Electrochemical Fabrication Methods Including Use
May 7, 2004 of Surface Treatments to Reduce Overplating and/or
Planarization During Formation of Multi-layer Three-Dimensional
Structures 10/387,958 Cohen, et al., Electrochemical Fabrication
Method and Application Mar. 13, 2003 for Producing
Three-Dimensional Structures Having Improved 2003-022168-A1 Surface
Finish Structures Having Improved Surface Finish Dec. 4, 2003
10/434,494 Zhang, et al., Methods and Apparatus for Monitoring
Deposition May 7, 2003 Quality During Conformable Contact Mask
Plating Operations 2004-0000489-A1 Jan. 1, 2004 10/434,289 Gang
Zhang, Conformable Contact Masking Methods and May 7, 2003
Apparatus Utilizing In Situ Cathodic Activation of a Substrate
20040065555 Apr. 8, 2004 10/434,294 Gang Zhang, Electrochemical
Fabrication Methods With May 7, 2003 Enhanced Post Deposition
Processing Enhanced Post Deposition 20040065550 Processing Apr. 8,
2004 10/434,295 Cohen, et al., Method of and Apparatus for Forming
Three- May 7, 2003 Dimensional Structures Integral With
Semiconductor Based 2004-0004001 Circuitry Jan. 8, 2004 10/434,315
Christopher A. Bang, Methods of and Apparatus for Molding May 7,
2003 Structures Using Sacrificial Metal Patterns 2003-0234179 Dec.
25, 2003 10/434,103 Cohen, et al., Electrochemically Fabricated
Hermetically Sealed May 7, 2004 Microstructures and Methods of and
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10/841,347 Cohen, et al., Multi-step Release Method for
Electrochemically May 7, 2004 Fabricated Structures 10/434,519
Dennis R. Smalley, Methods of and Apparatus for May 7, 2003
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2004-0007470 Via Selective Etching and Filling of Voids Jan. 15,
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[0142] Various other embodiments of the present invention exist.
Some of these embodiments may be based on a combination of the
teachings herein with various teachings incorporated herein by
reference. Some embodiments may not use any blanket deposition
process and/or they may not use a planarization process. Some
embodiments may involve the selective deposition of a plurality of
different materials on a single layer or on different layers. Some
embodiments may use blanket depositions processes that are not
electrodeposition processes. Some embodiments may use nickel as a
structural material while other embodiments may use different
materials such as gold, silver, or any other electrodepositable
materials that can be separated from the copper and/or some other
sacrificial material. Some embodiments may use copper as the
structural material with or without a sacrificial material. Some
embodiments may remove a sacrificial material while other
embodiments may not. In some embodiments, the depth of deposition
may be enhanced by pulling the conformable contact mask away from
the substrate as deposition is occurring in a manner that allows
the seal between the conformable portion of the CC mask and the
substrate to shift from the face of the conformal material to the
inside edges of the conformable material.
[0143] In view of the teachings herein, many further embodiments,
alternatives in design and uses of the instant invention will be
apparent to those of skill in the art. As such, it is not intended
that the invention be limited to the particular illustrative
embodiments, alternatives, and uses described above but instead
that it be solely limited by the claims presented hereafter.
* * * * *