U.S. patent application number 13/737709 was filed with the patent office on 2013-07-11 for masks for use in applying protective coatings to electronic assemblies, masked electronic assemblies and associated methods.
This patent application is currently assigned to HzO, Inc.. The applicant listed for this patent is Sidney Edward Martin, III, Max Sorenson, Blake Stevens. Invention is credited to Sidney Edward Martin, III, Max Sorenson, Blake Stevens.
Application Number | 20130176691 13/737709 |
Document ID | / |
Family ID | 48743781 |
Filed Date | 2013-07-11 |
United States Patent
Application |
20130176691 |
Kind Code |
A1 |
Stevens; Blake ; et
al. |
July 11, 2013 |
MASKS FOR USE IN APPLYING PROTECTIVE COATINGS TO ELECTRONIC
ASSEMBLIES, MASKED ELECTRONIC ASSEMBLIES AND ASSOCIATED METHODS
Abstract
One or more masks may be used to control the application of
protective (e.g., moisture-resistant, etc.) coatings to one or more
portions of various components of an electronic device during
assembly of the electronic device. A method for applying a
protective coating to an electronic device includes assembling two
or more components of the electronic device with one another. A
mask may then be applied to the resulting electronic assembly. The
mask may shield selected portions of the electronic assembly, while
other portions of the electronic assembly, i.e., those to which a
protective coating is to be applied, may remain exposed through the
mask. With the mask in place, application of a protective coating
to portions of the electronic assembly exposed through the mask may
commence. After application of the protective coating, the mask may
be removed from the electronic assembly. Embodiments of masked
electronic assemblies are also disclosed.
Inventors: |
Stevens; Blake; (Morristown,
NJ) ; Sorenson; Max; (Cottonwood Heights, UT)
; Martin, III; Sidney Edward; (Fairhaven, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Stevens; Blake
Sorenson; Max
Martin, III; Sidney Edward |
Morristown
Cottonwood Heights
Fairhaven |
NJ
UT
MA |
US
US
US |
|
|
Assignee: |
HzO, Inc.
Draper
UT
|
Family ID: |
48743781 |
Appl. No.: |
13/737709 |
Filed: |
January 9, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61584939 |
Jan 10, 2012 |
|
|
|
Current U.S.
Class: |
361/748 ;
118/505; 29/592.1 |
Current CPC
Class: |
B05C 21/005 20130101;
H05K 1/02 20130101; H05K 2203/0557 20130101; Y10T 29/49002
20150115; H01L 2924/0002 20130101; H05K 2203/0173 20130101; H01L
2924/0002 20130101; H05K 3/28 20130101; H01L 23/564 20130101; H01L
2924/00 20130101; H05K 3/0073 20130101; H01L 21/02299 20130101;
H01L 21/027 20130101; H05K 3/284 20130101 |
Class at
Publication: |
361/748 ;
118/505; 29/592.1 |
International
Class: |
H05K 3/28 20060101
H05K003/28; B05C 21/00 20060101 B05C021/00; H05K 1/02 20060101
H05K001/02 |
Claims
1. A method for coating an electronic device, comprising:
assembling a plurality of components of an electronic device to
form an electronic assembly; applying a mask to the electronic
assembly, the mask shielding at least a portion of the assembly;
applying a protective coating to at least two components of the
electronic assembly with the mask in place; and removing the mask
from the electronic assembly, the protective coating remaining on
coated portions of the electronic assembly, uncoated portions of
the electronic assembly being exposed through the mask.
2. The method of claim 1, wherein assembling the plurality of
components comprises assembling a plurality of components to be
located at least partially within an interior of the electronic
device.
3. The method of claim 1, further comprising: assembling at least
one exterior component of the electronic device with the electronic
assembly, the at least one exterior component defining at least a
portion of an interior of the electronic device, at least a portion
of the protective coating and at least a portion of the electronic
assembly located within the interior of the electronic device.
4. The method of claim 1, further comprising: applying a sealing
agent to the at least a portion of the electronic assembly before
applying the mask to the electronic assembly, the sealing agent
defining a seal between the mask and the electronic assembly upon
applying the mask to the electronic assembly.
5. The method of claim 1, wherein applying the mask comprises
assembling a preformed mask with the electronic assembly.
6. The method of claim 5, wherein removing the mask comprises
disassembling the preformed mask from the electronic assembly.
7. The method of claim 6, further comprising: cleaning the
preformed mask after disassembling the mask from the electronic
assembly.
8. The method of claim 6, further comprising: assembling the
preformed mask with another electronic assembly.
9. The method of claim 6, wherein assembling the preformed mask
with the electronic assembly comprises assembling a mask that
depresses at least one button of the electronic device with the
electronic device.
10. The method of claim 5, wherein assembling the preformed mask
comprises assembling a heat shrink mask with the electronic
assembly, then heating the heat shrink mask.
11. The method of claim 1, wherein applying the mask comprises
applying a masking material to the electronic assembly and defining
the mask from the masking material.
12. The method of claim 11, wherein applying the mask comprises
applying a radiation curable masking material to the electronic
assembly and exposing at least a portion of the radiation curable
masking material to radiation that will cure the radiation curable
masking material.
13. The method of claim 12, wherein applying comprises applying the
radiation curable material to selected portions of the electronic
assembly.
14. The method of claim 12, wherein exposing comprises exposing
selected portions of the radiation curable masking material to the
radiation.
15. The method of claim 11, wherein removing the mask comprises
mechanically removing the mask from the electronic assembly.
16. The method of claim 15, wherein removing the mask comprises
chemically removing the mask from the electronic assembly, the
chemically removing being effected without removing the protective
coating.
17. The method of claim 15, wherein removing the mask comprises
radiation processed-removing the mask from the electronic assembly,
the radiation processed-removing being effected without removing
the protective coating.
18. The method of claim 1, wherein applying the mask includes
applying the mask over at least one electrical contact, a light
emission element, an imaging element or a sensor of the electronic
assembly and, upon removing the mask, the at least one electrical
contact, the light emission element, the imaging element or the
sensor is exposed through the protective coating.
19. The method of claim 1, further comprising: after removing the
mask, assembling at least one additional component with the
electronic assembly; applying another mask to the electronic
assembly to shield at least a portion of the at least one
additional component; applying another protective coating over the
another mask and to at least a portion of the at least one
additional component exposed through the another mask; and removing
the another mask from the electronic assembly, the another
protective coating remaining on a coated portion of the additional
component, at least one uncoated portion of the electronic assembly
being exposed through the another mask.
20. An electronic assembly, comprising: an electronic assembly
including a plurality of assembled components of an electronic
device; and a mask over a portion of the electronic assembly.
21. The electronic assembly of claim 20, wherein the mask comprises
an apparatus removably assembled with the electronic assembly.
22. The electronic assembly of claim 21, further comprising: at
least one seal between the mask and the electronic assembly.
23. The electronic assembly of claim 20, wherein the mask comprises
a coating on the electronic assembly.
24. The electronic assembly of claim 20, further comprising: a
protective coating on the mask and at least one portion of the
electronic assembly exposed through the mask.
25. A mask configured for assembly with an electronic assembly,
comprising at least one preformed element configured for assembly
with and disassembly from an electronic assembly, the at least one
preformed element configured to shield at least a portion of the
electronic assembly, at least one aperture defined through the
preformed element to expose another portion of the electronic
assembly, and at least one protruding element configured to depress
at least one button of the electronic assembly while the at least
one preformed element is in an assembled relationship with the
electronic assembly.
26. The mask of claim 25, comprising a plurality of preformed
elements.
27. The mask of claim 26, wherein the plurality of preformed
elements are configured for assembly with one another.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] A claim for the benefit of priority to U.S. Provisional
Patent Application No. 61/584,939, filed on Jan. 10, 2012 and
titled METHODS FOR MASKING ELECTRONIC DEVICES FOR APPLICATION OF
PROTECTIVE RESISTANT COATINGS THERETO, MASKS FOR USE IN APPLYING
PROTECTIVE COATINGS TO ELECTRONIC DEVICES AND MASKED ELECTRONIC
DEVICES ("the '939 Provisional Application"), is hereby made under
35 U.S.C. .sctn.119(e). The entire disclosure of the '939
Provisional Application is, by this reference, incorporated
herein.
TECHNICAL FIELD
[0002] This disclosure relates generally to methods for applying
protective (e.g., moisture-resistant, etc.) coatings to electronic
assemblies. Such a method may include masking the electronic
assembly prior to application of a protective coating to the
electronic assembly. The present disclosure also relates to masks
that may be used to shield portions of an electronic assembly
during coating processes, as well as to masked electronic
devices.
SUMMARY
[0003] One or more masks may be used to control the application of
material of a protective coating, or "protective material," and,
thus, the application of a protective coating to one or more
portions of various components of an electronic device during
assembly of the electronic device. A mask may be planar or
substantially planar, or it may be nonplanar. The planarity (or
nonplanarity) of a mask may result from the planarity (or
nonplanarity) of the electronic assembly over which the mask is
formed (e.g., when conformal coating processes are used, when the
mask contacts or substantially contacts all of the portions of the
surface of the electronic assembly that it covers, etc.).
[0004] As used herein, the term "protective coating" includes
moisture-resistant coatings, as well as other coatings that protect
various parts of an electronic assembly from external influences.
The term "moisture resistant" refers to the ability of a coating to
prevent exposure of a coated element or feature to moisture. A
moisture-resistant coating may resist wetting or penetration by one
or more types of moisture, or it may be impermeable or
substantially impermeable to one or more types of moisture. A
moisture-resistant coating may repel one or more types of moisture.
In some embodiments, a moisture-resistant coating may be
impermeable to, substantially impermeable to or repel water, an
aqueous solution (e.g., salt solutions, acidic solutions, basic
solutions, drinks, etc.) or vapors of water or other aqueous
materials (e.g., humidity, fogs, mists, etc.), wetness, etc.). Use
of the term "moisture-resistant" to modify the term "coating"
should not be considered to limit the scope of materials from which
the coating protects one or more components of an electronic
device. The term "moisture resistant" may also refer to the ability
of a coating to restrict permeation of or repel organic liquids or
vapors (e.g., organic solvents, other organic materials in liquid
or vapor form, etc.), as well as a variety of other substances or
conditions that might pose a threat to an electronic device or its
components. Various aspects relating to the use of masks in the
application of protective coatings are disclosed.
[0005] In one aspect, a method for applying a protective coating to
an electronic device includes assembling two or more components of
the electronic device with one another. A mask may then be applied
to the resulting electronic assembly. The mask may shield selected
portions of the electronic assembly, while other portions of the
electronic assembly, i.e., those to which a protective coating is
to be applied, may remain exposed through the mask. With the mask
in place, application of a protective coating to portions of the
electronic assembly exposed through the mask may commence. After
application of the protective coating, the mask may be removed from
the electronic assembly. In some embodiments, one or more
additional components may then be added to an electronic assembly
to which a protective coating has been applied. Another mask may be
applied to this larger electronic assembly, and another protective
coating may then be applied to areas of the larger electronic
assembly that are exposed through the mask.
[0006] In some embodiments, the mask may be formed on the
electronic assembly. The mask may be selectively formed on, defined
on or applied to areas of the electronic assembly that are exposed,
but not to be covered with a protective coating. Without
limitation, such areas may include components from which a
protective coating may interfere with thermal transmission or
features whose functionality may be detrimentally affected by
protective coating. Non-limiting examples of the latter include
various transducers (e.g., audio elements, such as microphones,
speakers, etc.; camera lenses; etc.), features with moving parts
(e.g., silent mode vibrating elements, autofocus elements of camera
lenses, etc.), communication components (e.g., communication ports,
power ports, audio jacks, etc.), memory card receptacles (e.g., for
secure digital (SD) cards, subscriber identity module (SIM) cards,
universal serial bus (USB) or micro USB ports, etc.) and the
like.
[0007] A variety of techniques may be used to form a mask on an
electronic assembly, define a mask on an electronic assembly, or
otherwise selectively apply a mask to an electronic assembly. As
one example, a mask material may be selectively applied to areas of
the electronic assembly that are to remain free from coverage by a
protective coating. As another example, a mask material may be
applied over an entire area of an electronic assembly then
selectively removed from locations to which a protective coating is
to be applied.
[0008] After a protective coating has been applied to portions of
an electronic assembly exposed through a mask that was defined on
the electronic assembly, the mask may be selectively removed from
the electronic assembly. A mask that has been defined in place may
be mechanically removed from the electronic assembly. Some
non-limiting examples of mechanical removal include peeling and
abrasion (e.g., with frozen gas (e.g., carbon dioxide (CO.sub.2),
nitrogen (N.sub.2), etc.), corn starch, sand, glass, etc.).
Alternatively, a mask that has been defined in place may be
chemically removed from the electronic assembly. In embodiments
where chemical removal techniques are employed, the
defined-in-place mask may be removed with selectivity over the
material of the protective coating (i.e., the protective coating
may remain intact over desired locations of the electronic
assembly). Although selective chemical removal processes may not
have a significant chemical affect on portions of the protective
coating that were formed over the mask, those portions of the
protective coating may be "lifted off" of the electronic assembly
as the mask is chemically removed from the assembly.
[0009] In other embodiments, the mask may comprise a preformed
apparatus, which may include one or more elements configured to be
assembled with the electronic assembly and, optionally, with one or
more other elements of the preformed mask. When a preformed mask is
used in the application of a protective coating to an electronic
assembly, a seal or a sealing agent (e.g., an elastomer, etc.) may
be applied to a surface of the electronic assembly, and may reside
between the electronic assembly and the mask once the mask is in
place on the electronic assembly. In some embodiments, the seal may
comprise a part of the preformed mask that is configured for
assembly against the electronic assembly. A preformed mask may even
be formed from a solid elastomeric material that will function as a
seal. In other embodiments, a seal or sealing agent may be
configured for application to one or both of the preformed mask and
the electronic assembly before the preformed mask is assembled with
the electronic assembly. When sufficient force is applied to one or
both of the preformed mask and the electronic assembly in the
appropriate direction(s), the seal or sealing agent may define a
discrete boundary between each masked region and its adjacent
region(s) that is (are) to be covered with a protective coating to
prevent the introduction of protective material at locations
between the electronic assembly and the preformed mask and, thus,
may enable the formation of a protective coating with a discrete
periphery.
[0010] In embodiments where a sealing agent is applied to the
electronic assembly or mask, the sealing agent may comprise a
material that is configured for selective application. The sealing
agent may comprise an elastomer that may be viscous when first
applied and subsequently solidify to form a seal and, thus,
delineation between coated and uncoated regions. Non-limiting
examples of sealing agents that are initially viscous then solidify
include liquid latex and hot melt adhesive, which is typically
referred to as "hot glue." Alternatively, the sealing agent may
remain relatively viscous. Examples of sealing agents that remain
relatively viscous include gels, greases and other materials that
will maintain their viscosity when subjected to elevated
temperatures and/or pressures of the material deposition
process.
[0011] A preformed mask may comprise one or more features that
interact with corresponding features of the electronic assembly to
which they are configured to be assembled. In a specific
embodiment, a protruding feature may be positioned on an interior
surface of the preformed mask to depress a button of the electronic
assembly when the preformed mask is positioned on the electronic
assembly. In another specific embodiment, a a preformed mask may
include one or more features that prevent the introduction of
protective material into ports (e.g., communication ports, power
ports, audio jacks, etc.) or receptacles (e.g., SIM card
receptacles, memory card slots, etc.) of the electronic assembly.
These features may be configured to cover ports or receptacles to
keep the protective material out of these features, or these
features may be configured to be received by the ports or
receptacles.
[0012] Once the protective coating has been formed, a preformed
mask may be removed from an electronic assembly merely by
disassembling the mask from the electronic assembly. Thereafter,
the preformed mask may be cleaned. For example, protective material
may coat portions of the preformed mask. A residue of a sealing
agent may also remain on surfaces of the preformed mask following
its removal from the electronic assembly. Once the mask has been
cleaned, it may be reused; i.e., placed on another electronic
assembly to mask portions of that electronic assembly as a
protective coating is applied to other portions of the electronic
assembly.
[0013] An electronic assembly may be masked with a combination of
preformed elements and elements that are defined on the electronic
assembly. In some embodiments, both preformed and defined-in-place
mask elements may reside on an electronic assembly concurrently
and, thus, be used simultaneously. In other embodiments, one or
more mask elements that are defined in place may be used at a
different point in the process of assembling an electronic device
than masks that include one or more preformed elements.
[0014] Embodiments of masked electronic assemblies are also
disclosed. A masked electronic assembly includes an electronic
assembly and a mask. The mask may include one or more features that
are defined in place on the electronic assembly, one or more
preformed elements, or a combination of defined-in-place and
preformed elements.
[0015] Other aspects, as well as features and advantages of various
aspects, of the disclosed subject matter will become apparent to
those of ordinary skill in the art though consideration of the
ensuing description, the accompanying drawings and the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] In the drawings:
[0017] FIG. 1 illustrates an embodiment of a process in which a
protective coating is applied to a portion of an electronic
assembly, which process includes the assembly of at least two
components of an electronic device, application of a mask to the
electronic assembly formed by those components, application of the
protective coating to the electronic assembly, and removal of the
mask from the electronic assembly;
[0018] FIGS. 2 through 4 are schematic representations of
embodiments of electronic assemblies with masks and/or protective
coatings on some, but not all, areas of their surfaces;
[0019] FIG. 5 depicts an embodiment of a preformed mask configured
to be placed on and disassembled from surfaces of an electronic
assembly that are configured to be located within an interior of an
electronic device;
[0020] FIG. 6 shows an embodiment of a preformed mask with at least
one feature that interacts with a corresponding feature of an
electronic assembly or an electronic device when the preformed mask
is placed on the electronic assembly or electronic device; and
[0021] FIG. 7 illustrates an embodiment of a system for applying
protective coatings to electronic assemblies, showing a masking
element, a protective coating element and a de-masking element.
DETAILED DESCRIPTION
[0022] The disclosed subject matter, in various embodiments,
includes methods for shielding selected surfaces or features of
electronic assemblies during application of protective coatings
(e.g., moisture resistant coatings, etc.) to the electronic
assemblies and/or components of the electronic assemblies. A mask
may shield one or more features of the electronic assembly and/or
its components for a variety of reasons, including, without
limitation, to enable electrical connectivity between components
following application of the protective coating to the electronic
assembly, to provide access to interactive features of an
electronic device of which the electronic assembly is a part, for
aesthetic purposes (e.g., to limit or prevent application of the
protective coating to one or more exterior features of an
electronic device, such as a display, etc.), to prevent
interference with various components (e.g., features with moving
parts, transducers, communication components, card receptacles,
etc.), and to enable the transmission of light or other
electromagnetic radiation to or from one or more components of the
electronic assembly or a device of which the electronic assembly is
a part.
[0023] With reference to FIG. 1, a series of elements of a process
10 for applying a protective coating to an electronic assembly is
described, as are embodiments of the manner in which masking,
coating and related processes may fit into the process of
assembling a finished electronic device. Various embodiments of
electronic assemblies 100, 100', 100'' are shown in FIGS. 2 through
4.
[0024] At reference 20 of FIG. 1, and with added reference to FIG.
2, two or more components 102, 104 of an electronic device (e.g., a
circuit board (e.g., printed wiring board, ceramic board, etc.);
another carrier, such as a silicon interposer; etc.) and another
electronic component, such as a packaged semiconductor device, an
antenna, a display, another electronic subassembly including its
own circuit board, etc.; two components of an electronic device;
etc.) are assembled with one another. The resulting electronic
assembly 100 (which may comprise a finished electronic device or a
device under assembly, or a subassembly) may include features that
are to be located within a finished electronic device, features
that are to be located on the outside of the finished electronic
device or a combination of internal and external features.
[0025] In some embodiments, all or part of the electronic assembly
100 may be prepared before applying a mask 110 to selected areas of
the electronic assembly 100. Such preparation may include, but is
not limited to, processes that will enable the mask to limit the
application of one or more protective materials to masked areas of
the electronic assembly. As another option, preparation of an
electronic assembly may prevent adhesion of a mask to certain areas
that are to be exposed laterally beyond or through the mask. In yet
another option, an electronic assembly may be processed to
facilitate adhesion of a protective material to certain areas of
the electronic assembly to which a protective coating is to be
applied. Non-limiting examples of such processes include cleaning
processes, processes for applying certain materials (e.g.,
sealants, release agents, etc.), processes for imparting one or
more areas of a surface with a desired texture, and the like. In a
specific embodiment, FIG. 2 shows the application of a sealing
agent (e.g., by jetted printing, screen printing, spraying, etc.)
or a seal 112 (e.g., by assembly processes, etc.) to selected
portions of the electronic assembly 100. Alternatively, a seal 112
or sealing agent may be applied to selected portions of a preformed
embodiment of a mask 110, or to selected portions of both the
electronic assembly 100 and a preformed embodiment of a mask
110.
[0026] It may be desirable to prevent the application of a
protective coating to one or more surfaces 106 of the electronic
assembly 100; application of the protective coating may be limited
to unmasked portions 108 of the electronic assembly 100 (i.e.,
portions that are exposed through the mask 110). Accordingly, at
reference 22 of FIG. 1, a mask 110 is applied to the electronic
assembly. The mask 110 may be applied to an electronic assembly 100
in a way that prevents the protective material from contacting
areas of the electronic assembly 100 that are covered by the mask
110.
[0027] Manual or automated processes may be used to apply the mask
110 to the electronic assembly 100. A mask 110 may be formed or
otherwise defined on the electronic assembly 100, for example, by
applying a mask material to the electronic assembly 100. In some
embodiments, the mask material may comprise an unconsolidated
material, such as a liquid or uncured material. As an
unconsolidated mask material is applied to the electronic assembly
100, it may at least partially conform to the contour of the
electronic assembly 100. In some embodiments, including those where
the speed with which a mask may be removed is more desirable than
the extent to which high aspect ratio features are masked, the mask
110 may only partially conform to the contour of the area of the
electronic assembly 100 to which it applied. In other embodiments,
an unconsolidated mask material may be applied in a manner that
minimizes the likelihood that any gaps will form between the mask
110 and the electronic assembly 100, including situations where
reliable masking of high aspect ratio features is desired. In such
embodiments, the mask 110 may conform substantially or completely
to the contour of the area of the electronic assembly 100 to which
it is applied. The viscosity, temperature and/or other properties
of a masking material may affect its ability to conform and, thus,
the extent to which it conforms to a surface to which it is
applied. Once the mask material has been applied to selected
locations of an electronic assembly 100, the mask material may then
harden or cure. In some embodiments, the application of a mask 110
to an electronic assembly 100 may include additional processing. As
a non-limiting example, the mask material may be applied under
conditions (e.g., under a vacuum, etc.), at a temperature, etc.
that minimizes or prevents the occurrence of gaps between the mask
110 and the electronic assembly.
[0028] In some embodiments, a mask material may comprise one or
more films that are configured to be placed on and secured to the
electronic assembly 100. In some embodiments, such a masking film
may be subjected to conditions that hold it in place in the
electronic assembly 100 and/or secure it to the electronic assembly
100. In addition, a masking film may be subjected to conditions
that enable it to conform or substantially conform to the shape(s)
of the surface(s) to which the masking film is applied. Without
limitation, such conditions may include the selective application
of pressure to the masking film in a manner that forces it against
the surface(s) that are to be covered by a mask 110. As an example,
a positive pressure may be applied to force the masking film
against a desired location of the electronic assembly 100. As
another example, a negative pressure, such as a vacuum, may be
applied to a masking film to draw the masking film against the
electronic assembly 100. Optionally, positive pressure and negative
pressure may be employed in conjunction with one another; for
example, positive pressure may be momentarily applied (e.g., as a
burst of gas or air, etc.) to press the masking film against the
electronic assembly 100, then a negative pressure may draw the
masking film against the electronic assembly 100; holding it in
place on the electronic assembly 100. Heat may be applied to a
masking film to increase its pliability and, thus, its ability to
conform. Heat may also cause the masking film, or an adhesive on
the masking film, to adhere to the surface of the electronic
assembly. In embodiments where each film from which a mask 110 is
to be formed comprises a material that will shrink when heated, the
masking film and, optionally, the electronic assembly 100 may be
heated to enable the material to engage and/or adhere to features
of the electronic assembly 100 that it covers. A masking film may
have a thickness Nonlimiting examples of masking films that will
shrink when heated include polyethylene films (e.g., that marketed
by 3M Company of Maplewood, Minn., as Polyethylene Protective Tape
2E97C, etc.) and polyvinyl chloride (PVC) films. An adhesive
material (e.g., a pressure-sensitive adhesive, a silicone coating,
etc.) may be provided on a surface of the masking film to enable it
to be temporarily secured to a substrate before it is heated. The
thickness of a masking film may depend upon the desired thickness
of the mask and, thus, may comprise any of a wide range of
thicknesses. By way of non-limiting example, in specific
embodiments, a masking film may have a thickness of about 2 mils
(i.e., about 0.05 mm) to about 4 mils (i.e., about 0.1 mm).
[0029] Masks 110 that are formed on electronic assemblies 100 may
be configured for compatibility with the process(es) that will be
used to form a protective coating on one or more parts of the
electronic assembly 100. As an example, relatively thin masks 110
may be used when a protective coating will be formed by directional
or anisotropic deposition processes to avoid the occurrence of
unprotected areas adjacent to the outer periphery of the mask 110,
which might otherwise occur due to shadowing if the mask 110 were
thicker. As another example, when anisotropic deposition processes
will be used to form a protective coating, masks 110 with openings
that have one or more dimensions that exceed the mean free path of
particles or molecules of protective material may be used to ensure
that the thickness throughout the protective coating is uniform.
Conversely, a protective coating may be formed with areas that have
different thicknesses than one another by forming a mask 110 with
at least one opening that has one or more dimensions that exceed
the mean free path of the particles or molecules that will form the
protective coating and at least one opening that has one or more
dimensions that are smaller than the mean free path of the
particles or molecules of protective material that will form the
protective coating. In yet another example, masks 110 that maintain
good adhesion with, and remain in close contact with, electronic
assemblies 100 when subjected to the conditions under which
protective layers are formed are useful with a variety of different
processes, including isotropic (i.e., multi-directional or from all
directions) deposition processes, where protective material might
otherwise creep under the edges of a mask 110.
[0030] Alternatively, a preformed mask 110 may be placed on, or
assembled with, the electronic assembly 100. Assembly of the
preformed mask 110 with the electronic assembly 100 may be effected
in such a way that the preformed mask 110 exerts force against the
electronic assembly 100, which may hold the preformed mask 110 in
place and prevent exposure of areas covered by the preformed mask
110 to protective material. Such force may be achieved by
application of pressure or force. For example, a negative pressure,
such as a vacuum, may be applied to the mask 110 to pull it against
the electronic assembly 100. As another example, a positive
pressure or force may be applied to the mask 110 to hold it against
the electronic assembly 100.
[0031] A mask 110 that incorporates teachings of this disclosure
may have a three-dimensional structure. In some embodiments, a mask
110 may extend over portions of surfaces of an electronic assembly
100 that face in opposite or substantially opposite directions. As
an example, a mask 110 may cover at least portions of opposite
surfaces of an electronic assembly 100 or of a component of an
electronic assembly 100. In another example, a mask 110 may cover
opposing, or facing, spaced-apart surfaces of two or more
components.
[0032] Turning now to FIG. 3, and at reference 24 of FIG. 1, with
the mask 110 in place, a protective coating 120 may be selectively
applied to unmasked portions 108 of the electronic assembly 100'. A
variety of processes may be used to apply a protective coating 120
to unmasked portions 108 of the electronic assembly 100',
including, without limitation, those disclosed by U.S. patent
application Ser. No. 13/736,753, filed on Jan. 8, 2013 and titled
SYSTEMS FOR ASSEMBLING ELECTRONIC DEVICES WITH INTERNAL MOISTURE
RESISTANT COATINGS ("the '753 application") and those disclosed by
U.S. patent application Ser. No. 13/735,862, filed on Jan. 7, 2013
and titled ELECTRONIC DEVICES WITH INTERNAL MOISTURE RESISTANT
COATINGS ("the '862 application"). The entire disclosures of both
the '753 application and the '862 application are, by this
reference, incorporated herein.
[0033] Thereafter, at reference 26 of FIG. 1, the mask 110 may be
removed from the electronic assembly 100', leaving the protective
coating 120 on selected portions (i.e., the previously exposed
portions 108) of the electronic assembly 100'. An illustrative
embodiment of the resulting electronic assembly 100'' is shown in
FIG. 4.
[0034] The masking and coating processes could occur during
assembly of an electronic device and/or once assembly of the
electronic device is complete. A mask may be applied manually, by
automated equipment, or by a combination of both manual and
automated processes. When masking and coating occur during assembly
of an electronic device, the mask may be applied to an electronic
assembly 100 (FIG. 2) immediately before a protective coating is
formed on the electronic assembly 100, or the mask may be applied
to the electronic assembly 100 at one or more points during the
assembly process that are most convenient or at which application
of the mask 100 are most easily achieved. In some embodiments, more
than one protective coating may be applied to an electronic
assembly and/or its components, in various stages of assembly.
Accordingly, an assembly process may include a plurality of masking
processes, a plurality of coating processes and a plurality of mask
removal, or "de-masking," processes.
[0035] In embodiments where a protective coating is applied to a
finished electronic device 100''' (which may take the place of the
electronic device 100 in the process depicted by FIG. 1), some
disassembly of the electronic device 100''' may provide access to
the components that require masking.
[0036] Masking and coating may be followed by removal of the mask.
When the mask has been formed on an electronic assembly 100 (FIG.
2) or on an electronic device 100''', it may be removed
mechanically (e.g., by peeling, abrasion, etc.), chemically (e.g.,
by etching or dissolving material of the mask with selectivity over
removal of the protective coating, etc.), by radiation (e.g., with
laser beams, electron beams, X-rays, high intensity light, etc.),
or by any other suitable means for mask removal. In embodiments
where the mask comprises one or more preformed elements (see, e.g.,
FIGS. 5 and 6), removal of the mask may comprise disassembly of the
mask from the electronic assembly 100 (FIG. 2).
[0037] Individual components of an electronic assembly or the
interior of an electronic device may be shielded from application
of a material that forms a protective coating. These components may
include electrical contacts, light transmission elements (e.g.,
cameras, projectors, etc.), sensors, and other components. These
components may be masked with a reusable or disposable system that
is specifically configured for the component geometry and location.
This system may include a predetermined number of contact covers
that can be applied to the electronic devices. The covers could be
affixed by an adhesive, an elastic/pressure connection, a static
connection, and/or geometrical constraints. This system could be
made from multiple material types for both structural support and
to ensure uniform contact to the shielded component. The points of
contact to the electronic assembly or electronic device may
uniformly and effectively seal the shielded feature or component
from the protective coating deposition. These contact points may
comprise a soft material (e.g., a polymer, such as silicone or
latex, etc.), a grease, a gel, a curable liquid, or the like.
[0038] A preformed mask 110', such as that depicted by FIG. 6, may
be configured to shield the exterior of a finished electronic
device 100''' from a protective coating material. A preformed mask
110' may have any of a variety of configurations. Without
limitation, a preformed mask 110' may include a snap-in fixture; a
multi-part fixture that snaps or adheres together; a shrink-wrap
coating that is activated by heat, UV radiation, or some other
curing mechanism; a silicone or other polymer type cover; a cover
that uses static or Van der Waals interactions to adhere; a gel or
liquid that is applied to the exterior and cured; and masks that
are printed directly on to the device exterior. A preformed mask
may be disposable (i.e., configured to be used once) or it may be
reusable. Following use, a reusable embodiment of a preformed mask
may be cleaned other otherwise prepared before it is again applied
to an electronic assembly or an electronic device.
[0039] In embodiments where the electronic device 100''' includes
one or more interface elements 108 (e.g., buttons, dials, switches,
etc.), it may be desirable to shield one or more of the interface
elements 108 from the protective coating. In some embodiments, it
may be desirable to ensure that an interface element 108 (e.g., a
button, switch, etc.) will make the necessary electrical contacts
when placed in an "on" or connected position. In such embodiments,
the preformed mask 110' may include one or more features 118'
(e.g., protrusions, etc.) for engaging a corresponding interface
element 108 in the desired position (e.g., by depressing a button,
by holding a switch in the appropriate position, etc.).
Alternatively, one or more inserts may be assembled with the
electronic device 100''' and/or the preformed mask 110'. In any
embodiment, the material and/or construction of the preformed mask
110' (e.g., its rigidity, stiffness, elasticity, shape, etc.) may
enable such a feature 118' to accomplish its intended task.
[0040] In an alternative embodiment, an external feature (e.g., a
tension band, etc.) may be assembled or otherwise used in
conjunction with a mask (preformed or formed on the electronic
assembly or electronic device) to apply any force needed to engage
and maintain an interface element 118' in a desired position while
a protective coating is applied to all or part of an electronic
assembly 100 (FIG. 2) or electronic device 100'''.
[0041] In embodiments where the mask is formed on an electronic
assembly or an electronic device, all or part of the electronic
assembly or electronic device may be masked by applying a masking
material that may cure or otherwise harden to define a mask. As a
non-limiting example, the masking material may comprise a liquid
material or a gel material that may harden or cure over time or
that may be cured by exposure to heat, a catalyst, electromagnetic
(e.g., ultraviolet (UV), etc.) radiation, or another curing agent
or condition.
[0042] In some embodiments, a selectively curable material (e.g., a
radiation curable material, etc.) may also, or alternatively, be
employed as a moisture-resistant coating on portions of an
electronic component, an assembly of electronic components, or an
electronic device.
[0043] In another aspect, a system for applying a protective
coating to an electronic assembly (see, e.g., the '753 application
and the '862 application) may include a masking element, or
station, that is configured to form a mask in accordance with
teachings of this disclosure. Additionally, such a system may
include one or more mask removal elements, or stations, also
employing teachings of this disclosure. FIG. 7 illustrates an
embodiment of a system 200 for applying protective coatings to
electronic assemblies, showing a masking element 210, a protective
coating element 220 and a de-masking element 230. As a plurality of
protective coatings may be applied to an electronic assembly, or
electronic assemblies at various stages of assembly, during the
assembly components to manufacture an electronic device, a system
200 may include a corresponding number of masking elements 210,
protective coating elements 220 and de-masking elements 230.
[0044] Although the foregoing description contains many specifics,
these should not be construed as limiting the scope of any of the
appended claims, but merely as providing information pertinent to
some specific embodiments that may fall within the scopes of the
appended claims. Features from different embodiments may be
employed in combination. In addition, other embodiments of the
disclosed subject matter may also be devised which lie within the
scopes of the appended claims. The scopes of the claims are,
therefore, indicated and limited only by the plain language used in
each claim and the legal equivalents to the elements recited by the
claims. All additions, deletions and modifications to the disclosed
subject matter that fall within the meaning and scopes of the
claims are to be embraced by the claims.
* * * * *