U.S. patent application number 09/826623 was filed with the patent office on 2002-02-21 for component for use in forming printed circuit boards.
This patent application is currently assigned to GA-TEK Inc. (dba Gould Electronics Inc.). Invention is credited to Centanni, Michael A., Kusner, Mark.
Application Number | 20020020549 09/826623 |
Document ID | / |
Family ID | 24571803 |
Filed Date | 2002-02-21 |
United States Patent
Application |
20020020549 |
Kind Code |
A1 |
Centanni, Michael A. ; et
al. |
February 21, 2002 |
Component for use in forming printed circuit boards
Abstract
A component for use in manufacturing printed circuits that in a
finished printed circuit constitutes a functional element. The
component is comprised of a film substrate formed of a first
polymeric material having a first side and a second side. At least
one layer of a tiecoat metal is applied to the first side of the
film substrate. At least one layer of copper on the at least one
layer of a tiecoat metal, the layer of copper having an essentially
uncontaminated exposed surface facing away from the at least one
layer of tiecoat metal. A plurality of spaced apart, adhesion
promoting areas of a tiecoat metal are provided on the second side
of the film substrate defining regions of exposed polymeric
material on the second side of the film substrate.
Inventors: |
Centanni, Michael A.;
(Parma, OH) ; Kusner, Mark; (Gates Mills,
OH) |
Correspondence
Address: |
MARK KUSNER COMPANY LPA
HIGHLAND PLACE SUITE 310
6151 WILSON MILLS ROAD
HIGHLAND HEIGHTS
OH
44143
|
Assignee: |
GA-TEK Inc. (dba Gould Electronics
Inc.)
|
Family ID: |
24571803 |
Appl. No.: |
09/826623 |
Filed: |
April 5, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09826623 |
Apr 5, 2001 |
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09641303 |
Aug 18, 2000 |
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6316733 |
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Current U.S.
Class: |
174/259 |
Current CPC
Class: |
H05K 3/388 20130101;
H05K 3/025 20130101; H05K 3/4611 20130101 |
Class at
Publication: |
174/259 |
International
Class: |
H05K 001/02 |
Claims
1. A component for use in manufacturing printed circuits that in a
finished printed circuit constitutes a functional element, said
component comprised of: a film substrate formed of a first
polymeric material having a first side and a second side; at least
one layer of a tiecoat metal applied to said first side of said
film substrate; at least one layer of copper on said at least one
layer of a tiecoat metal, said layer of copper having an
essentially uncontaminated exposed surface facing away from said at
least one layer of tiecoat metal; and a plurality of spaced apart,
discrete, adhesion promoting areas formed of a tiecoat metal on
said second side of said film substrate, said adhesion promoting
areas defining regions of exposed polymeric material on said second
side of said film substrate.
2. A component as defined in claim 1, wherein said first polymeric
material is polyimide.
3. A component as defined in claim 2, wherein said adhesion
promoting areas define a continuous region of exposed polymeric
material.
4. A component as defined in claim 2, wherein said tiecoat metal is
selected from the group consisting of chromium, nickel, titanium,
aluminum, molybdenum, tantalum, gold, tin, indium, vanadium,
silicon, iron, copper and alloys thereof.
5. A component as defined in claim 4, wherein said tiecoat has a
thickness of between 0.ANG. and about 500.ANG..
6. A component as defined in claim 5, wherein said copper layer has
a thickness between about 0.1 .mu.m and about 70 .mu.m.
7. A component as defined in claim 6, wherein said copper layer has
a thickness of about 0.2 .mu.m.
8. A component as defined in claim 6, wherein said polyimide film
has a thickness of between about 12.5 .mu.m and about 125
.mu.m.
9. A component as defined in claim 1, wherein said first polymeric
material is a polyimide, and said component is further comprised of
a dimensionally stable adhesive film applied to said second side of
said film substrate.
10. A component as defined in claim 9, wherein said adhesive is
selected from the group consisting of acrylics, epoxies, nitrite
rubbers, phenolics, polyamides, polyarylene ethers,
polybenzimidazoles, polyesters, polyimides, polyphenylquinoxalines,
polyvinyl acetals, polyurethanes, silicones, vinyl-phenolics,
urea-formaldehyde and combinations thereof.
11. A component as defined in claim 10, wherein said adhesive film
is an epoxy having a thickness between about 1 mil to about 3
mils.
12. A component as defined in claim 9, further comprising a metal
support substrate that constitutes a discardable element in the
formation of a printed circuit board, one surface of said metal
support substrate being essentially uncontaminated and engageable
with said layer of copper, said support substrate attached to said
layer of copper at its periphery to define a substantially
uncontaminated central zone of copper inwardly of the edges of the
copper layer.
13. A component for use in manufacturing printed circuits that in a
finished printed circuit constitutes a functional element, said
component comprised of: a film substrate formed of a first
polymeric material having a first side and a second side; at least
one layer of a tiecoat metal applied to said first side of said
film substrate; at least one layer of copper on said at least one
layer of a tiecoat metal, said layer of copper having an
essentially uncontaminated exposed surface facing away from said at
least one layer of tiecoat metal; and a plurality of spaced apart,
discrete, adhesion promoting areas formed of a tiecoat metal on
said second side of said film substrate, said adhesion promoting
areas defining regions of exposed polymeric material on said second
side of said film substrate; an uncured adhesive on said second
side of said film substrate; and a metal support substrate that
constitutes a discardable element in the formation of a printed
circuit board, one surface of said metal support substrate being
essentially uncontaminated and engageable with said layer of
copper, said support substrate attached to said layer of copper at
its periphery to define a substantially uncontaminated central zone
of copper inwardly of the edges of the copper layer.
14. A multi-layer printed circuit, comprising: a) an inner core
formed from one or more printed circuit laminates, said printed
circuit laminates comprised of a core substrate having a first
surface with a strip conductor disposed thereon, and b) at least
one surface laminate, comprised of: a film substrate formed of a
first polymeric material; at least one layer of a flash metal
applied to a first side of said film substrate; at least one layer
of copper on said layer of flash metal; a plurality of spaced
apart, discrete, adhesion promoting areas formed of a metal or
metal alloy on the second side of said film substrate; and an
adhesive layer between said surface laminate and said inner
core.
15. A multi-layer printed circuit as defined in claim 14, wherein
said inner core is comprised of a reinforced polymer.
16. A multi-layer printed circuit as defined in claim 14, wherein
said inner core is comprised of a non-reinforced polymer.
17. A method of forming a multi-layer printed circuit, comprising
the steps of: a) forming an inner core from one or more printed
circuit laminates, each of said printed circuit laminates having a
core substrate and a first surface with a strip conductor disposed
thereon; b) forming at least one surface laminate, said surface
laminate comprised of: a film substrate formed of a first polymeric
material; at least one layer of a flash metal applied to a first
side of said film substrate; at least on layer of copper on said
layer of flash metal; a plurality of spaced apart, discrete,
adhesion promoting areas formed of a metal or metal alloy on the
second side of said film substrate; an adhesive layer between said
surface laminate and said inner core; and c) compressing said inner
core and said surface laminate together under conditions of heat
and pressure to create a first multi-layer printed circuit.
18. A method as defined in claim 17, further comprising the step
of: d) forming a strip conductor from the layer of copper on the at
least one surface laminate.
19. A method as defined in claim 17, further comprising the step
of: e) drilling a through hole through said surface laminate
connecting a strip conductor on said inner core with a strip
conductor on said surface laminate.
Description
Field of the Invention
[0001] The present invention relates generally to printed circuits,
and more particularly, to components used in the manufacturing of
printed circuit boards and other articles.
BACKGROUND OF THE INVENTION
[0002] A basic component of a printed circuit board is a dielectric
layer having a sheet of copper foil bonded thereto. Through a
subtractive process, that includes one or more etching steps,
portions of the copper foil are etched away to leave a distinct
pattern of conductive lines and formed elements on the surface of
the dielectric layer. Multi-layer printed circuit boards are formed
by stacking and joining two or more of the aforementioned
dielectric layers having printed circuits thereon.
[0003] The trend, in recent years, has been to reduce the size of
electronic components and provide printed circuit boards having
multi-chip modules, etc. This results in a need to increase the
number of components, i.e., surface mount components, provided on a
printed circuit board. A key to providing a densely populated
circuit board is to produce close and fine circuit patterns from
the copper. The width and spacing of conductive paths on the
printed circuit board are generally dictated by the thickness of
the copper on the dielectric layer.
[0004] It has been proposed to use copper-coated polyimide
components in forming printed circuits. The thickness of the copper
on polyimide is generally significantly less than the thickness of
traditional copper foil sheet. The thinner copper on the polyimide
allows for finer and more closely spaced circuit lines in that the
thinness of the copper layer reduces the etching time required to
remove unwanted copper. In this respect, it is possible to use
copper clad polyimide wherein the copper has a thickness as low as
0.1 .mu.m (1,000 .ANG.). The thinner copper on the polyimide also
finds advantageous application in a semi-additive process. In a
semi-additive process, the copper is masked to define a circuit
pattern, and copper is plated onto the exposed pattern to build up
a circuit. The mask material is removed and a "flash etch" removes
the base copper on the polyimide leaving the built-up circuit on
the polyimide. Thus, copper on polyimide finds advantageous
application in both subtractive and semi-additive processes for
forming printed circuits.
[0005] The use of copper-coated polyimide components in forming
printed circuit boards or multi-layer laminates requires good
adhesion between the polyimide side of the component and the inner
core laminate to which it is attached. However, it is generally
known that polyimide itself has relatively poor adhesion
properties.
[0006] The present invention overcomes this and other problems, and
provides a copper-coated polyimide component having improved
adhesion with the inner core laminate.
SUMMARY OF THE INVENTION
[0007] In accordance with a preferred embodiment of the present
invention, there is provided a component for use in manufacturing
printed circuits that in a finished printed circuit constitutes a
functional element. The component is comprised of a film substrate
formed of a first polymeric material having a first side and a
second side. At least one layer of a tiecoat metal is applied to
the first side of the film substrate. At least one layer of copper
is deposited on the at least one layer of a tiecoat metal, the
layer of copper having an essentially uncontaminated exposed
surface facing away from the at least one layer of tiecoat metal. A
plurality of spaced apart, discrete, adhesion promoting areas of a
tiecoat metal are formed on the second side of the film substrate
to define region(s) of exposed polymeric material on the second
side of the film substrate.
[0008] It is an object of the present invention to provide a
copper-coated polyimide component for use in forming printed
circuit boards, multi-layer laminates and the like.
[0009] It is another object of the present invention to provide a
copper-coated polyimide component as described above having
improved adhesion to an inner core laminate.
[0010] It is another object of the present invention to provide a
copper-coated polyimide component as described above having an
adhesion promoting layer on the polyimide side of the
component.
[0011] It is another object of the present invention to provide a
copper-coated polyimide component as described above wherein the
adhesion promoting layer is comprised of a plurality of spaced
apart, discrete areas defining region(s) of exposed polyimide.
[0012] It is a still further object of the present invention to
provide a copper-coated polyimide component as described above that
would accommodate through holes.
[0013] These and other objects will become apparent from the
following description of a preferred embodiment taken together with
the accompanying drawings and the appended claims.
BRIEF DESCRIPTION OF THE INVENTION
[0014] The invention may take physical form in certain parts and
arrangement of parts, a preferred embodiment of which will be
described in detail in the specification and illustrated in the
accompanying drawings which form a part hereof, and wherein:
[0015] FIG. 1 is a top, perspective view of a component for use in
forming printed circuit boards and multi-layer laminates,
illustrating a preferred embodiment of the present invention;
[0016] FIG. 2 is a bottom, perspective view of the component shown
in FIG. 1;
[0017] FIG. 3 is a perspective view showing a mask used in forming
the component shown in FIGS. 1 and 2;
[0018] FIG. 4 is a perspective view illustrating a metal deposition
process for forming the component shown in FIGS. 1 and 2;
[0019] FIG. 5 is a bottom, perspective view of a component for use
in forming printed circuit boards and multi-layer laminates,
illustrating another embodiment of the present invention;
[0020] FIG. 6 is a bottom, perspective view of a component for use
in forming printed circuit boards and multi-layer laminates,
illustrating a further embodiment of the present invention;
[0021] FIG. 7 is an exploded view of a portion of a printed circuit
board, showing the component shown in FIG. 1 with trace lines
formed thereon; and
[0022] FIG. 8 is a perspective view showing a component for use in
forming printed circuit boards and multi-layer laminates,
illustrating another embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0023] Referring now to the drawings wherein the showings are for
the purpose of illustrating preferred embodiments of the invention
only, and not for the purpose of limiting same, FIG. 1 shows a
component 10 for use in manufacturing articles such as printed
circuit boards, illustrating a preferred embodiment of the present
invention.
[0024] Broadly stated, component 10 is comprised of a film
substrate 12 formed of a first polymeric material. Substrate 12 has
a first side 12a and a second side 12b. At least one flash layer 14
of a tiecoat metal (conventionally referred to as a "tiecoat") is
applied to first side 12a of film substrate 12. A layer 16 of
copper is applied onto flash layer 14. An adhesion promoting
material is provided on second side 12b of film substrate 12.
Component 10 is adapted to be a functional element in a finished
printed circuit. In this respect, copper layer 16 would be
processed so as to form printed circuit patterns on film substrate
12.
[0025] Polymeric film 12 is preferably formed of a polyimide and
has a thickness of between 12.51 .mu.m and 125 .mu.m. Specific
examples of materials that may form polymeric film 12 include
Kapton-E or Kapton-HN (manufactured by I.E. DuPont) Upilex-S or
Upilex-SGA (manufactured by Ube) and Apical NP (manufactured by
Kaneka).
[0026] Tiecoat layer 14 may be formed from metals from the group
consisting of chromium, nickel, titanium, aluminum, molybdenum,
tantalum, gold, tin, indium, vanadium, silicon, iron, copper and
alloys thereof. Tiecoat layer 14 preferably has a thickness of
between 0.ANG. (none) and 500.ANG., and more preferably, between
about 50.ANG. to 300.ANG..
[0027] Copper layer 16 preferably has a thickness of between about
0.1 .mu.m (1000.ANG.) and 70 .mu.m. Layer 16 will generally be
formed of a flash layer of copper (not shown) onto which a
relatively thicker layer of copper is deposited. Layer 16, as
referred to hereinafter and as shown in the drawings, is intended
to describe the total thickness of the copper layer that is on the
tiecoat flash layer 14. The copper forming copper layer 16 may be
applied by vacuum metallization, electrodeposition, electroless
deposition or combinations thereof. Depending upon the thickness of
copper layer 16, the major portion of copper layer 16 is preferably
applied by an electrodeposition process or by vacuum metallization.
Methods of vacuum metallization include thermal evaporation,
sputtering and e-beam deposition. Copper layer 16 has an exposed
surface, designated 16a in the drawings that is essentially
uncontaminated. As used herein, the term "uncontaminated" shall
refer to the surface 16a of copper layer 16 being free from dust,
grease, oil, resin particles and other like materials that are
deleterious when present on the copper to the formation of a
printed circuit by either a subtractive process or a semi-additive
process. Surface 16a may include a surface treatment typically
applied to the copper to promote adhesion of a dielectric substrate
or to provide other properties and still be "uncontaminated" as
used herein. Surface 16a of copper layer 16 may be treated or
untreated without deviating from the present invention.
[0028] As indicated above, the overall thickness of copper layer 16
may vary between about 0.1 .mu.m (1000.ANG.) and 70 .mu.m. Copper
thicknesses at the lower side of this range, ire., about 0.1 .mu.m,
would typically be applied by a vacuum metallization process and
find application in a semi-additive process as heretofore
described. Copper thicknesses of about 5 .mu.m and above may be
applied by an electrodeposition process, or by a combined process
involving vacuum metallization and electrodeposition. Copper
thicknesses of about 5 .mu.m and above may be processed in a number
of ways (including a semi-additive process), whereas copper having
a thickness of about 18 .mu.m and above, would typically find
application in a subtractive process, as described above.
[0029] Referring now to second side 12b of film 12, an adhesion
promoting material is applied thereto to promote adhesion of
component 10 to a substrate, as shall be described in greater
detail below. The adhesion promoting material is preferably formed
of a metal selected from the group consisting of chromium, nickel,
titanium, aluminum, molybdenum, tantalum, gold, tin, indium,
vanadium, silicon, iron, copper and alloys thereof. In this
respect, the adhesion promoting material is preferably formed of
the same metals used to form tiecoat layer 14.
[0030] In a preferred embodiment, the adhesion promoting material
is disposed on surface 12b as a plurality of discrete, spaced-apart
areas 22, as best seen in FIG. 2. In the embodiment shown in FIGS.
1-4, areas 22 are squares that are equally spaced and uniformly
sized. It will be appreciated from a further reading of the
specification, that areas 22 may assume shapes other than square,
such as rectangular, circular, triangular and the like, and may be
irregular in size, shape and spacing. Areas 22 preferably have a
thickness between about 50.mu. to about 300.ANG.. As best seen in
FIG. 2, contiguous region(s) of surface 12b of polyimide film 12
are left exposed by adhesion promoting areas 22.
[0031] Adhesion promoting areas 22 are formed on second side 12b of
polymeric film 12 by a deposition process, such as vacuum
metallization, electrodeposition or combinations thereof. In the
embodiment shown, a sputter deposition process is used. A mask 52,
best seen in FIG. 3, is used to form adhesion promoting areas 22.
Mask 52 may be formed of a paper, or as shown in FIG. 3, of a
polymeric material. Mask 52 has openings 54 formed therethrough.
Openings 54 conform to the desired shape of adhesion promoting
areas 22. Mask 52 is placed over, i.e., onto, second side 12b of
polymeric film 12. An electron beam gun 62, schematically shown in
FIG. 4, directs a stream of electrons 64 at a target 66, that is
comprised of the metal that is to be deposited. Metal atoms and
agglomerates, designated 68 in FIG. 4, liberated by electron beam
64 are deposited onto second side 12b of film 12 through openings
54 in mask 52 to define adhesion promoting areas 22. When mask 52
is removed, a pattern of adhesion promoting areas 22, as shown in
FIG. 2, is provided.
[0032] Component 10 is adapted for use in forming a printed circuit
board, a multilayer printed circuit board, a multi-layer laminate
or the like. Specifically, component 110 is adapted to be secured
to a core. (Throughout this specification, the use of the term
"core" is meant to include any one of a variety of core materials,
all of which may be reinforced or non-reinforced and may include an
epoxy, polyester, polyimide, a polytetrafloroethylene, and in some
applications, a core material which includes previously formed
printed circuits). Adhesion promoting areas 22 are adapted to
enhance the adhesion of film 12 to the core. The core may be
circuitized and have circuit trace lines formed on the exposed
surface thereof. An adhesive is disposed between such circuit trace
lines on the core and component 10. Component 10 is placed upon the
core with adhesion promoting areas 22 facing the adhesive and the
core. Using conventionally known laminating techniques, component
10 is secured to the core, leaving copper layer 16 exposed for
circuitizing as the outermost layer of a multi-layer circuit board.
It is conventionally known to connect circuit trace lines on the
outer surface to circuit trace lines embedded within the
multi-layer printed circuit by means of "through holes."
[0033] FIG. 7 illustrates component 10 as part of a multi-layer
printed circuit board 70, wherein component 10 is an outermost
section of the printed circuit board and is attached to a core 80.
FIG. 7 is shown exploded to illustrate more clearly the respective
elements. Only a portion of core 80 is shown in FIG. 7. Core 80 may
be formed from one or more previously formed printed circuit
laminates, wherein each printed circuit laminate is comprised of an
inner core having circuit leads or connectors formed on the outer
surfaces thereof.
[0034] In FIG. 7, an inner core 80 having circuit trace lines
designated 82, 84, 86 and 88 thereon, is shown.
[0035] A layer of adhesive 74 is disposed between core 80 and
component 10. Adhesion promoting areas 22 enhance the adhesion of
component 10 to core 80. Component 10 has been circuitized to have
trace lines 92, 94 thereon. The respective components shown in FIG.
7 are laminated together using conventionally known techniques.
FIG. 7 illustrates how ends 92a, 92b, 94a and 94b of circuit trace
lines 92, 94 may be connected to ends 82a, 84a, 86a and 88a of
trace lines 82, 84, 86 and 88, by means of through holes designated
102 (shown in phantom in FIG. 7). As will be appreciated, through
holes 102 are drilled through the respective layers after their
assembly and lamination. Trace line 92 on component 10 is oriented
to be connected to trace lines 82, 84 on core 80. As shown in FIG.
7, through holes 102 that connect trace line 92 to trace lines 82,
84 extend through region 24 where no adhesion promoting area(s) 22
exists, i.e., through holes 102 do not intersect with adhesion
promoting areas 22. Trace line 94 on component 10 is disposed to be
connected to ends 86a, 88a of trace lines 86, 88 on core 80. Each
through hole 102 that connects trace line 92 to trace lines 86, 88
extends through an adhesion promoting area 22, as shown in FIG. 7.
In this respect, since adhesion promoting areas 22 are isolated
from each other, and only one through hole 102 extends through each
area 22, no short circuit condition exists.
[0036] The present invention thus illustrates how component 10 may
be used to enhance adhesion of a polymeric material to a substrate
without interfering with through hole connections between the
respective layers of a multi-layer printed circuit board. It will,
of course, be appreciated that adhesion promoting areas 22 must be
dimensioned in conjunction with the trace line patterns such that
one and only one through hole 102 penetrates an adhesion promoting
area 22 to avoid a short circuit condition.
[0037] FIGS. 1-4 show a component 10 formed to have a plurality of
discrete, spaced apart adhesion promoting areas 22 formed by a mask
pattern. As will be appreciated by those skilled in the art, other
shapes and patterns may be formed using a reusable mask or using a
masking material that is etched away. For example, FIG. 5 shows a
component 10' illustrating an alternate embodiment of the present
invention, wherein adhesion promoting areas, designated 22', are
shown in the form of staggered strips. This type of configuration
may also be formed by using a reusable mask, or by using a masking
material that is later dissolved away following an
electrodeposition process to apply adhesion promoting material to
side 12b of film 12.
[0038] FIG. 6 shows another component 10" illustrating another
embodiment of the present invention, wherein a masking material is
applied at specific, designated locations 32 prior to
electrodepositing an adhesion promoting layer 22" onto surface 12b
of polyimide film 12. Following the deposition of the adhesion
promoting layer 22", the masking material is etched away leaving
exposed regions of surface 12b of polyimide film 12 at locations
32. Component 10" is suitable for use in circuit boards, wherein
through hole locations within the boards are known, and locations
32 may be positioned accordingly.
[0039] As heretofore described, in its broadest embodiment, the
present invention relates to a copper-on-polyimide component 10
having adhesion promoting areas 22 formed of a metal on the
polyimide side thereof. Referring now to FIG. 8, another embodiment
of the present invention is shown. FIG. 8 shows a component 10, as
heretofore described, having a metallic support substrate 212
adhered to copper layer 16 along the periphery thereof. Support
substrate 212 is provided as a protective layer to prevent
contamination of copper layer 16, as disclosed in Assignee's
co-pending U.S. patent application No. 09/397,404, entitled "Copper
Coated Polyimide With Metallic Protective Layer," filed on Sep. 16,
1999, the disclosure of which is expressly incorporated herein by
reference, and further to provide structural rigidity to component
10 to prevent excessive bending or flexing of component 10 and to
prevent cracking or breaking of areas 22. FIG. 8 also shows an
adhesive layer 222 formed of a dimensionally stable adhesive
applied to component 10 over adhesion promoting areas 22. Adhesive
layer 222 is provided for ready attachment of component 10 onto an
inner core. Adhesive layer 222 is preferably formed of a
dimensionally stable, uncured or semi-cured adhesive. A material
available under the name "High Performance Epoxy Adhesive Bonding
Film 9901/9902" manufactured by Minnesota Mining Manufacturing (3M)
finds advantageous application to the present invention, and
provides a dimensionally stable, uncured resin suitable for
application in forming the component structures disclosed
heretofore.
[0040] The present invention thus provides a component 10 for use
in the manufacturing of printed circuit boards or other articles.
Component 10 is basically a polymer-supported, thin layer of
copper, i.e., comprised of polymeric film layer 12, tiecoat layer
14 and copper layer 16, having adhesion promoting areas 22 thereon.
In use, polymeric film layer 12 is adapted to be attached to a
core, with adhesion promoting areas 22 enhancing adhesion of film
layer 12 to the core. Exposed, copper layer 16 is then utilized in
either a subtractive process or a semi-additive process as
described above to create a circuit pattern on polymeric film layer
12. As indicated above, the thickness of copper layer 16 formed on
polymeric film layer 12 will vary depending upon the process used.
Component 10 is thus suitable for various processes for forming
printed circuits. Polymeric film layer 12 with an adhesion
promoting material thereon provides a suitable surface for
attachment to a dielectric substrate.
[0041] The foregoing description is a specific embodiment of the
present invention. It should be appreciated that this embodiment is
described for purposes of illustration only, and that numerous
alterations and modifications may be practiced by those skilled in
the art without departing from the spirit and scope of the
invention. It is intended that all such modifications and
alterations be included insofar as they come within the scope of
the invention as claimed or the equivalents thereof.
* * * * *