U.S. patent application number 09/907971 was filed with the patent office on 2001-12-20 for circuit board and a method for making the same.
Invention is credited to Achari, Achyuta, Belke, Robert Edward, Glovatsky, Andrew Zachary, Goenka, Lakhi N., Gordon, Robert Joseph, Krautheim, Thomas Bernd, Li, Delin, Nation, Brenda Joyce.
Application Number | 20010052423 09/907971 |
Document ID | / |
Family ID | 26902441 |
Filed Date | 2001-12-20 |
United States Patent
Application |
20010052423 |
Kind Code |
A1 |
Achari, Achyuta ; et
al. |
December 20, 2001 |
Circuit board and a method for making the same
Abstract
A method for making a multi-layer electronic circuit board 136
having electroplated apertures 96, 98 which may be selectively and
electrically isolated from an electrically grounded member 46 and
further having selectively formed air bridges and/or crossover
members 128 which are structurally supported by material 134.
Inventors: |
Achari, Achyuta; (Canton,
MI) ; Glovatsky, Andrew Zachary; (Plymouth, MI)
; Belke, Robert Edward; (West Bloomfield, MI) ;
Nation, Brenda Joyce; (Troy, MI) ; Li, Delin;
(San Jose, CA) ; Goenka, Lakhi N.; (Ann Arbor,
MI) ; Gordon, Robert Joseph; (Livonia, MI) ;
Krautheim, Thomas Bernd; (Belleville, MI) |
Correspondence
Address: |
John G. Chupa
Chupa & Alberti, P.C.
Suite 205
31313 Northwestern Highway
Farmington Hills
MI
48334
US
|
Family ID: |
26902441 |
Appl. No.: |
09/907971 |
Filed: |
March 20, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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60207647 |
May 26, 2000 |
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Current U.S.
Class: |
174/255 ;
174/250; 174/261; 174/262 |
Current CPC
Class: |
H05K 3/06 20130101; H05K
3/445 20130101; H05K 3/44 20130101; H05K 2201/09881 20130101; H05K
3/4623 20130101; H05K 2201/0355 20130101; H05K 2203/0369 20130101;
H05K 3/4611 20130101; H05K 2201/0352 20130101; H05K 2203/1184
20130101; H05K 2201/0305 20130101; H05K 3/4685 20130101; H05K
2201/0379 20130101; H05K 2203/1152 20130101; H05K 2201/09563
20130101; Y10T 29/49156 20150115; H05K 2201/09609 20130101; H05K
3/4038 20130101; H05K 3/4641 20130101; H05K 2201/09509 20130101;
H05K 3/4608 20130101; H05K 2203/066 20130101; H05K 2203/0733
20130101; H05K 2201/0361 20130101; H05K 2201/09845 20130101; H05K
2201/09309 20130101; H05K 3/062 20130101; H05K 3/0047 20130101;
H05K 3/064 20130101; H05K 3/429 20130101; H05K 2203/1536 20130101;
H05K 3/4069 20130101; H05K 2201/09554 20130101; H05K 2201/0397
20130101 |
Class at
Publication: |
174/255 ;
174/250; 174/261; 174/262 |
International
Class: |
H05K 001/11 |
Claims
What is claimed is:
1. A circuit board comprising: a first electrically conductive
member having a first and a second surface; a first dielectric
member which is coupled to said first surface; a second dielectric
member which is coupled to said second surface; a first circuit
assembly having a second electrically conductive member which is
coupled to said first dielectric member, said first circuit
assembly further including a third electrically conductive member
and a first core member which is contained between said second and
said third electrically conductive members and which includes at
least one air-bridge; and a second circuit assembly having a fourth
electrically conductive member which is coupled to said second
dielectric member, said second circuit assembly further including a
fifth electrically conductive member and a second core member which
is contained between said fourth and said fifth electrically
conductive members and which includes at least one air-bridge, said
second circuit assembly cooperating with said first circuit
assembly and with said first and second dielectric material and
with said first electrically conductive member to form a
multi-layer circuit board.
2. The circuit board of claim 1 further comprising material which
supports said at least one air-bridge of said first circuit
assembly.
3. The circuit board of claim 1 wherein said first and second core
members comprise aluminum and wherein said first electrically
conductive member comprises copper.
4. The circuit board of claim 1 further comprising a first aperture
having a first surface which extends through said first, second,
third, fourth, and fifth electrically conductive members, said
first and second dielectric members, and said first and second core
members.
5. The electronic circuit board of claim 4 further comprising a
second aperture which has a second surface which is electrically
isolated from said first electrically conductive member.
6. The circuit board of claim 5 wherein said first electrically
conductive member is coupled to an electrical ground potential.
7. The circuit board of claim 5 wherein said first and second
apertures contain electroplated material upon said respective first
and second surfaces.
8. A method for making an electrical circuit assembly comprising
the steps of: providing a first member having a first core portion
which is contained between a top and a bottom layer; providing a
second member having a second core portion which is contained
between a top and a bottom layer; providing first layer and a
second layer of a first material; providing a third member;
removing a portion of said top and said bottom layer of said first
member, thereby exposing at least two portions of said core portion
of said first member; removing a portion of said top and said
bottom layer of said second member, thereby exposing at least two
portions of said core portion of said second member; creating a
first pre-circuit assembly by attaching the first layer of said
first material to a first surface of said third member, attaching
the second layer of said first material to a second surface of said
third member, attaching said first member to said first layer of
said first material, and attaching said second member to said
second layer of said first material; creating an aperture through
said first pre-circuit assembly, thereby causing a portion of said
first pre-circuit assembly to be contained within said created
aperture; applying an electrically conductive material to said
portion of said first pre-circuit assembly which is contained
within said aperture; and selectively removing portions of said
first and second core portions, thereby creating a circuit assembly
having at least one air-bridge and forming an electrical circuit
assembly.
9. The method of claim 8 wherein said third member comprises an
electrical ground plane and wherein said method further comprises
the step of isolating said portion of said first pre-circuit
assembly which is contained within said aperture from said third
member.
10. The method of claim 8 wherein said first material comprises a
dielectric adhesive material.
11. The method of claim 8 wherein said core portion of said first
member comprises aluminum and wherein said top and bottom layers
each comprise copper.
12. The method of claim 8 further comprising the step of creating a
first aperture within a certain portion of said third member; and
extending said first aperture through said first pre-circuit
assembly.
13. The method of claim 8 further comprising the step of applying
said electrically conductive material to certain portions of said
top layer of said first member and said bottom layer of said second
member.
14. The method of claim 8 wherein said step of selectively removing
portions of said core portion comprises the step of selectively
etching said core.
15. The method of claim 9 further comprising the steps of creating
a second aperture through said first pre-circuit assembly, thereby
exposing a second surface of said first pre-circuit assembly within
said second aperture, said second surface including a portion of
said third member.
16. The method of claim 9 wherein said step of applying an
electrically conductive material to said portion of said first
pre-circuit assembly comprises the step of electroplating copper
material upon said portion of said first pre-circuit assembly.
17. A method for making a circuit board comprising the steps of:
forming a first pre-circuit assembly having a first core member
having a first and a second surface, said first pre-circuit
assembly further including a first plurality of electrically
conductive members disposed upon said first surface and a second
plurality of electrically conductive members disposed upon said
second surface; forming a second pre-circuit assembly having first
and second circuit boards which are selectively attached to a
dielectric adhesive material and which cooperatively form a
separation region; coupling said dielectric adhesive material to
said second plurality of electrically conductive portions; removing
certain portions of said first core member, thereby forming at
least one pedestal portion which abuts one of said separation
regions; and extending said separation region through said at least
one pedestal portion, thereby forming a circuit board.
18. The method of claim 17 wherein said core member comprises
aluminum.
19. The method of claim 18 wherein said first and second plurality
of electrically conductive members each comprise copper.
20. The method of claim 19 wherein said step of removing said
certain portions of said first core member comprises selectively
etching said first core member.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to an electronic circuit board
and a method for making an electronic circuit board and more
particularly, to a multi-layer electronic circuit board having
metallized apertures which are selectively isolated and/or
disconnected from an electrical ground plane and further having
selectively formed air bridges and/or crossover circuits.
BACKGROUND OF THE INVENTION
[0002] Multi-layer circuit boards operatively receive electronic
components and allow the received components to be desirably
interconnected and to selectively and cooperatively form electrical
circuits. Particularly, these components are operatively received
upon opposed board surfaces and within certain interior portions of
the board, thereby desirably allowing each of the electronic
circuit boards to contain a relatively large amount of components
which efficiently, respectively, and densely populate the
respective boards.
[0003] It is desirable to allow each of the component containing
surfaces or portions of a created and/or formed electronic circuit
board to communicate and/or be selectively interconnected, thereby
allowing the contained electronic components to cooperatively and
selectively form a relatively large number of desired electrical
circuits. This desired communication and/or interconnection
typically requires the use of shared electrical ground planes, the
transmittal of electrical power and/or control type signals between
some or all of the component containing surfaces or board portions,
and/or the connection of components on each of the opposed surfaces
and/or within and between certain of the interior portions and the
top and/or bottom and/or other board surfaces.
[0004] This desired interconnection typically requires that one or
more holes be formed or drilled through each of the circuit boards,
thereby creating at least one "through hole" or "via" traversing
between each of the opposed component containing surfaces and
through the various interior circuit board portions. Typically this
drilling process is relatively complex and time consuming, thereby
increasing the overall circuit board production cost. This drilling
process also undesirably damages and/or destroys many of the
circuit boards, thereby further increasing overall production
costs.
[0005] Further, it is desirable to form "air-bridges" or "crossover
type circuits" upon one or more selected surfaces and/or within
certain component containing portions of the formed circuit board
in order to allow multiple levels of circuits and/or electrical
interconnections to be formed upon a single board surface and/or
within a certain component containing portion of the circuit board,
thereby desirably increasing the amount of electrical circuits
which may be created upon and/or within the created circuit board
(e.g., increasing the density of the contained electrical
circuitry).
[0006] These "air-bridges" or crossover circuits are typically
formed by rather complicated, costly, and time consuming processes.
The formed bridges and crossover circuits further do not typically
and efficiently accommodate certain desirable circuit board
interconnection processes, techniques, and/or methodologies such as
and without limitation, the use of relatively heavy wire bonding
(e.g., aluminum wire having a diameter of about five to about
twenty millimeters) or the direct connection of components to a
surface of the board.
[0007] There is therefore a need to provide an electronic circuit
board and a method for producing a multi-layer electronic circuit
board which overcomes some or all of the previously delineated
drawbacks of prior electronic circuit boards and methods for making
a circuit board, which selectively allows grounded and non-grounded
"vias" to be desirably and selectively and efficiently formed in a
cost effective manner, and which further allows for the efficient
and selective formation of air-bridge members or crossover circuits
which desirably accommodate diverse types of circuit
interconnection processes, and which increase the circuitry density
within the formed electronic circuit board.
SUMMARY OF THE INVENTION
[0008] It is a first object of the present invention to provide an
electronic circuit board and a method for producing an electronic
circuit board which overcomes some or all of the previously
delineated drawbacks of prior multi-layer electronic circuit boards
and of prior electronic circuit board forming methodologies and
techniques.
[0009] It is a second object of the invention to provide a method
for producing a multi-layer electronic circuit board which
overcomes some or all of the previously delineated drawbacks of
prior multi-layer electronic circuit board forming methodologies
and techniques, which allows for the formation or creation of an
electronic circuit board which selectively receives various
electronic components, which allows for the selective, efficient,
and reliable formation of metallized apertures, within the formed
and/or created electronic circuit board, which cooperatively allow
for communication by and between these various electronic
components and which further cooperatively allow for the selective
interconnection of these contained components.
[0010] It is a third object of the invention to provide a method
for producing a multi-layer electronic circuit board which
overcomes some or all of the previously delineated drawbacks of
prior multi-layer electronic circuit board forming methodologies
and techniques and which allows for the selective formation of
metallized apertures within a circuit board, which may be
selectively connected or disconnected and/or selectively isolated
from a formed electrical ground plane or bus.
[0011] It is a fourth object of the invention to provide a method
for producing a multi-layer electronic circuit board which
overcomes some or all of the previously delineated drawbacks of
prior multi-layer electronic circuit board forming methodologies
and techniques and which allows for the selective and efficient
formation of air bridges and/or crossover circuits and/or crossover
members which are adapted to accommodate a wide variety of
component interconnections, assemblies, techniques, and/or
methodologies.
[0012] According to a first aspect of the present invention, a
method for making an electric circuit board is provided. The method
includes the steps of providing a first member having a core which
is contained between a first and a second layer of material;
providing a second member having a core which is contained between
a first and a second layer of material; providing a first and a
second layer of a first material; providing a third member;
removing a portion of the top and the bottom layer of the first
member, thereby exposing a first and a second portion of the core
of the first member; removing a portion of the top and bottom layer
of the second member, thereby exposing a first and a second portion
of the core of the second member; creating a first pre-circuit
assembly by attaching the first layer of first material to a first
surface of the third member, attaching the second layer of first
material to a second surface of the third member, attaching the
first member to the first layer of first material, and attaching
the second member to the second layer of first material; creating
an aperture through the first pre-circuit assembly, thereby
exposing a first surface of the first pre-circuit assembly within
the aperture; applying an electrically conductive material to the
exposed first surface of the third pre-circuit assembly; and
selectively removing portions of the core, thereby creating at
least one air-bridge and forming an electrical circuit
assembly.
[0013] According to a second aspect of the present invention a
circuit assembly is provided. The circuit assembly is made by the
process of forming a first pre-circuit assembly having a first core
member having a first and a second surface, a first plurality of
electrically conductive members disposed upon the first surface,
and a second plurality of electrically conductive members disposed
upon the second surface; forming a second pre-circuit assembly
having first and second circuit boards which are selectively
attached to a dielectric adhesive material and which cooperatively
form a separation region; coupling the dielectric adhesive material
to the second plurality of electrically conductive portions;
removing certain portions of the first core member, thereby forming
a pedestal portion which abuts the separation region; extending the
separation through the pedestal portion, thereby forming a circuit
board.
[0014] According to a third aspect of the present invention, a
circuit board is provided and comprises a first electrically
conductive member having a first and a second surface; a first
dielectric member which is coupled to the first surface; a second
dielectric member which is coupled to the second surface; a first
circuit assembly having a second electrically conductive member
which is coupled to the first dielectric member, the first circuit
assembly further including a third electrically conductive member
and a first core member which is contained between the second and
the third electrically conductive members and which includes at
least one air-bridge; and a second circuit assembly having a fourth
electrically conductive member which is coupled to the second
dielectric member, the second circuit assembly further including a
fifth electrically conductive member and a second core member which
is contained between the fourth and the fifth electrically
conductive members and which includes at least one air-bridge, the
second circuit assembly cooperating with the first circuit assembly
and with the first and second dielectric material and with the
first electrically conductive member to form a multi-layer circuit
board.
[0015] These and other objects, aspects, and advantages of the
present invention will become apparent upon reading the following
detailed description in combination with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1(a)-(m) are successive sectional side views of a
multi-layer circuit board being produced and/or formed in
accordance with the teachings of the preferred embodiment of the
invention;
[0017] FIG. 2 is a top perspective fragmented view of the
multi-layer circuit board assembly shown in FIG. 1(l);
[0018] FIGS. 3(a)-(f) are successive sectional side views of a
multi-layer circuit board assembly being produced and/or formed in
accordance with the teaching of a second embodiment of the
invention; and
[0019] FIGS. 4(a)-(f) are successive sectional side views of a
multi-layer circuit board assembly being produced and/or formed in
accordance with the teachings of a third embodiment of the
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE
INVENTION
[0020] Referring now to FIGS. 1(a)-(m), there is shown a process 10
for making an electronic circuit board assembly in accordance with
the teachings of the preferred embodiment of the invention.
Particularly, process 10 begins by obtaining and/or providing a
member 12 having a first core portion 14 which is operatively
contained between a top and a bottom layer or a top or first and a
bottom or second member 16, 18, as best shown in FIG. 1(a). It
should be appreciated that the terms "first" and "second" should
not be limited to the layers and/or members to which they
specifically refer to within this specification (e.g., the term
"first" may alternatively refer to bottom layer or member 18).
[0021] In one non-limiting embodiment of the invention, core
portion or member 14 comprises conventional and commercially
available aluminum material while layers/members 16, 18 comprise
conventional, commercially available and substantially identical
electrically conductive material, such as copper. As further shown
best in FIG. 1(a), certain portions of layers/members 16, 18 are
removed by a conventional etching process in order to create
selectively formed apertures 20 within the layers 16, 18, thereby
creating exposed "areas" or surface portions 22, 24, 26, 28, 30,
32, 34, 36, 38, and 40 of the core member 14. In one non-limiting
embodiment of the invention, portions or pairs 22, 32; 24, 34; 26,
36; 28, 38; and 30, 40 are respectively aligned (e.g., portions 32,
34, 36, 38, 40 are respectively and wholly resident under portions
22, 24, 26, 28, and 30, and portions 32, 34, 36, 38, and 40 are
respectively identical in size and shape to portions 22, 24, 26,
28, and 30). In a further non-limiting embodiment of the invention,
portions 22, 24, 26, 28, 30, 32, 34, 36, 38, and 40 are each
substantially similar in size and shape.
[0022] In one non-limiting embodiment of the invention, the
thickness of the core member 14 is about fifty to two hundred
micrometers while the thickness of portions 16, 18 is substantially
identical and is about five to one hundred micrometers. Other
sizes, shapes, thicknesses, and/or dimensions of members 14-18 may
be utilized.
[0023] Process 10, as shown best in FIGS. 1(b) and 1(d), requires
the acquisition and/or creation of substantially identical layers
or members 42, 44 each of which, in one non-limiting embodiment,
comprise substantially identical and commercially available layers
of dielectric adhesive material having a substantially identical
size, shape, and thickness.
[0024] Process 10, as shown best in FIG. 1(c), further requires the
acquisition and/or creation of an electrically conductive member or
layer 46 which, in one non-limiting embodiment, is formed from
conventional and commercially available electrically conductive
material such as copper having a thickness, in one non-limiting
embodiment, ranging from about five micrometers to about one
hundred fifty micrometers. Further, at least one aperture or "hole"
48 is created within the member or layer 46 by drilling, punching,
and/or etching. As shown later, this at least one aperture 48 will
selectively form a "non-grounded" via or "through hole".
[0025] As shown best in FIG. 1(e), process 10 further requires the
acquisition and/or creation of a second member 50 which is
substantially similar to member 12. More particularly, member 50
includes a core portion or member 52 which is substantially similar
to core portion 14, and top or first and bottom or second members
or layer portions 54, 56 which are substantially and respectively
similar to member/layer portions 16, 18. Layers 54, 56 each have
several selectively formed apertures 58 which are effective to
cause member 50 to have exposed top surface portions 60, 62, 64,
66, 68 and exposed bottom surface portions 70, 72, 74, 76, 78. In
one embodiment of the invention, portions 60, 70; 62, 72; 64, 74;
66, 76; and 68, 78 are aligned (e.g., portions 74, 72, 70, 76, and
78 are respectively and wholly resident under portions 64, 62, 60,
66, and 68 and portions 74, 72, 70, 76, and 78 are respectively
identical in size and shape to portions 64, 62, 60, 66, and 68). In
a further embodiment of the invention, portions 60, 62, 64, 66, 68,
70, 72, 74, 76, 78 are each substantially similar in shape and
size.
[0026] A pre-circuit assembly 92 is formed in the fifth step of the
process 10, which is shown best in FIG. 1(f). Particularly, layer
18 of member 12 is attached by a conventional process or method to
the top surface 80 of member or layer 42, effective to allow
portions of layer 42 to overlay the previously formed apertures 20
within the layer 18, and more particularly, to overlay the exposed
portions 32, 34, 36, 38, 40. The bottom surface 82 of member or
layer 42 is attached, by a conventional process or method, to the
top surface 84 of layer or member 46, thereby overlaying the
previously formed aperture 48 and causing a portion of the member
42 to fill the aperture 48. The bottom surface 86 of the member 46
is attached, by a conventional process or method, to the top
surface 88 of the layer or member 44 and the attached surface 88
overlays the previously formed aperture 48. Further, the bottom
surface 90 of the layer 44 is attached, in a conventional manner,
to the top layer 54 of member 50, effective to overlay apertures 58
within layer 54 and to, more particularly, overlay exposed portions
60, 62, 64, 66, and 68. This formed pre-circuit assembly 92 is best
shown in FIG. 1(f).
[0027] As best shown in FIG. 1(g), process 10 continues with the
creation of a pre-circuit assembly 94 which is created by
selectively forming first and second apertures 96, 98 within the
formed pre-circuit assembly 92. These apertures 96, 98 may be
formed by drilling, etching, punching, or by any other conventional
process or methodology. Particularly, the first aperture 96 is
aligned with (e.g., extends through) the previously created
aperture 48 and effectively extends the previously created aperture
48 through the formed pre-circuit assembly 94. The second aperture
98, in one non-limiting embodiment, is substantially identical in
shape and size to the aperture 96 and is aligned with (e.g.,
extends through) apertures 30, 40. It should be realized that
apertures 96, 98 may be of various sizes and shapes and that
nothing in this description should or is meant to limit these
apertures 96, 98 to any certain size or shape.
[0028] Exposed surfaces 100, 102 of pre-circuit assembly 94 are
respectively contained within and/or reside within and/or define
the apertures 96, 98 and form respective "interior surfaces" of
apertures 96, 98. In one non-limiting embodiment of the invention,
member 46 functions as or comprises an electrical ground plane
(i.e., member 46 is physically and electrically coupled to a source
of electrical ground potential). As shown, member 46 does not
reside within aperture 96 and does not reside upon surface 100.
Hence, interior surface 100 is electrically isolated and/or
electrically disconnected from member 46, thereby causing aperture
96 to be a "non-grounded via" or a "non-grounded aperture". Member
46 does reside within aperture 98 and does reside upon surface 102.
Hence, interior surface 102 is electrically connected to member 46,
thereby causing aperture 98 to be a "grounded via" or a "grounded
aperture".
[0029] In the eighth step of process 10, which is shown best in
FIG. 1(h), a certain substance or material 104 is applied upon
exposed portions 106 of layers 14, 42, 44, 52 which reside within
apertures 96, 98 and which reside upon and/or which form an
integral part of surfaces 100, 102, thereby forming pre-circuit
assembly 108, having a top surface 110 and a bottom surface
112.
[0030] In one non-limiting embodiment of the invention, the
dielectric adhesive material layers or members 42, 44, 52, and 14
which are contained within portion 106 are "metallized" by using
known "direct metallization" methods or by use of conventional
electroless methods and/or by use of an electrically conductive
layer 104 which is formed upon the adhesive surface 106. The
applied material 104 may, in one non-limiting embodiment, comprise
palladium alloy, carbon, graphite, or copper or any other suitable
and/or similar material. It should be appreciated that material 104
is applied to these dielectric adhesive members or layers 14, 42,
44, 52 to "metallize" the exposed portions 106. Material 104 is
similarly bonded to these respective portions of conductive members
16, 18, 46, 54, and 56 which reside within the apertures 96, 98,
thereby allowing for the creation of a continuous electrically
conductive layer over aperture boundary or defining surfaces 100,
102.
[0031] In the ninth step of process 10, which is best shown in
FIGS. 1(i), a conventional and commercially available "resist"
material 114 is applied and/or "screen printed" in a conventional
and known manner upon most of the exposed portions of layer 16 and
layer 14 and upon most of the layers 52 and 56, effective to cause
certain portions 116 of layer 16 and certain portions 118 of layer
56 to remain exposed, and to form a pre-circuit assembly 120.
Particularly, in one non-limiting embodiment, these certain
portions of layers 116, 118 are proximate to the respective and
previously formed apertures 96, 98.
[0032] In the tenth step of process 10, which is best shown in FIG.
1(j), a conventional and commercially available copper material 122
is applied (e.g., electroplated) upon the certain exposed portions
116, 118 and also, in one non-limiting embodiment, upon the
material 104 covering the first and second surfaces 100, 102,
thereby forming a pre-circuit assembly 124.
[0033] In the eleventh step of process 10, which is shown best in
FIG. 1(k), material 114 is removed by a conventional process or
methodology, thereby forming a pre-circuit assembly 126. In the
twelfth step of process 10, as best shown in FIG. 1(l) and FIG. 2,
the members 14, 52 are selectively etched in order to selectively
form air-bridges or crossover members 128, thereby creating a
multi-layer circuit assembly 130. The formed air-bridge or
crossover members 128, in one non-limiting embodiment,
cooperatively form a void 132.
[0034] In the twelfth step of process 10, which is shown best in
FIGS. 1(m), a conventional and commercially available polymer
material 134 is applied to pre-circuit assembly 130 to
substantially "fill" the void 132, thereby "underfilling" and
structurally supporting the formed air bridges or crossover members
128 and creating a pre-circuit assembly 136.
[0035] It should be appreciated that the selective etching of core
members 14, 52 allows the air bridges and/or crossover members 128
to be efficiently and relatively easily formed in a cost effective
manner. Further, such etching allows for the selective formation of
air bridges and/or crossover members 128 which may have a selected
shape and/or size, thereby allowing the selectively and etchably
created air bridges and/or crossover members 128 to support a wide
variety of circuits and components, effective to selectively and
efficiently accommodate a wide variety of circuit interconnection
methodologies and/or techniques. Further, the structural support
given to the formed air bridges or crossover members 128 allows the
air-bridges or crossover members 128 to support relatively heaving
wiring and/or components, thereby increasing the overall utility of
the formed circuit assembly 136.
[0036] It should further be appreciated that the apertures 96, 98
may also be efficiently formed and/or created in a "single step"
operation which obviates the need to separately drill or create
apertures in each member/component which selectively forms the
created multi-layer circuit assembly 136, thereby increasing the
overall efficiency of process 10.
[0037] Referring now to FIGS. 3(a)-(f), there is shown a process
140 for making an electronic circuit board assembly in accordance
with the teachings of an alternate embodiment of the invention.
Particularly, process 140 begins by obtaining and/or providing a
pre-circuit assembly 142 having a core portion or member 144. As
shown, several electrically conductive portions or members 146 are
contained and/or disposed upon the top or first surface 147 of
member 144, and several electrically conductive portions or members
148 are contained and/or disposed upon the bottom or second surface
149 of member 144, as shown best in FIG. 3(a). In one non-limiting
embodiment of the invention, core portion 144 comprises
conventional and commercially available aluminum material while
layers/members 146, 148 comprise conventional, commercially
available, and substantially identical electrically conductive
material, such as copper. Hence, member 142 comprises, in one
non-limiting embodiment, a "copper clad aluminum member".
[0038] In the second step of process 140, as shown best in FIG.
3(b), a layer of adhesive material 150 is acquired and/or created
having a top or first surface 152 and a bottom or second surface
154. Virtually any type of adhesive material may be selectively
utilized within this process 140.
[0039] In the third step of process 140, as shown best in FIG.
3(c), a pre-circuit assembly 156 is provided. Particularly, in one
non-limiting embodiment, pre-circuit assembly 156 is comprised of
or includes a core portion 158 which contains apertures 160, 162,
164. Particularly, core portion 158 contains a first electrically
conductive layer or member 166 which is disposed on top or first
surface 167 and a second electrically conductive layer or member
168 which is disposed on bottom or second surface 169. As shown,
members 166, 168 each include apertures which are aligned with a
unique one of the respective apertures 160, 162, and 164. In one
non-limiting embodiment of the invention, core portion 158
comprises conventional and commercially available laminate material
while layers/members 166, 168 comprise conventional, commercially
available, and substantially identical electrically conductive
material, such as copper.
[0040] In another non-limiting embodiment of the invention, core
portion 158 may be formed from a wide variety of conventional and
commercially available individual circuit boards 159(a)-159(d) such
as a conventional "FR-4" or a conventional "rigid circuit board".
As shown, boards/portions 159(a) and 159(b) are separated by a
separation distance, region, or aperture 164; portions 159(c) and
159(b) are separated by a separation distance, region, or aperture
162; and portions 159(b) and 159(a) are separated by a separation
distance, region, or aperture 160. It should be appreciated that
selective numbers of "pre-formed" and commercially available boards
159(a-d) may be utilized within assembly 140.
[0041] In the fourth step of process 140, as shown best in FIG.
3(d), portions 148 of pre-circuit assembly 142 are attached to the
top surface 152 of material 150. Material 166 of pre-circuit
assembly 156 is attached to the bottom surface 154 of material 150,
thereby forming pre-circuit assembly 170. It should be realized
that circuit assembly 156 may be formed/created concurrently with
assembly 140, or separately. Moreover, the use of commercially
available circuit assemblies 159(a)-159(d) reduces the overall cost
of process 140 and allows for the use of the created circuit
assemblies in a wide variety of applications. Moreover, separate
fabrication and/or creation of assemblies 142 and 156 allows for
the separate creation of power traces and allows for a more
efficient creation of the final circuit board assembly.
[0042] In the fifth step of process 140, as best shown in FIG.
3(e), process 140 continues by applying a certain etchant material
(e.g., an aluminum etchant material) to certain selective portions
of core portion 144, effective to remove or "etch away" certain
selective portions of core portion 144, thereby forming pillar
portions 172(a)-(e) of core portion 144 which reside upon the top
surface 152 of material 150 and which may selectively overlay
apertures 160, 162, 164, thereby forming pre-circuit assembly
174.
[0043] In the sixth step of process 140, as shown best in FIG.
3(f), process 140 continues by drilling or otherwise causing
apertures 160, 162, 164 to extend through pre-circuit assembly 174
and through pillars 172(a), 172(c), 172(e), thereby forming
pre-circuit assembly 176. It should be appreciated that apertures
160, 162, 164 may be electroplated or processed in a manner which
allows for apertures 160, 162, 164 to form circuit
interconnections.
[0044] Referring now to FIGS. 4(a)-(e), there is shown a process
180 for making an electronic circuit board assembly in accordance
with the teachings of an alternate embodiment of the invention.
Particularly, process 180 begins by obtaining and/or providing a
pre-circuit assembly or a member 182 having a core portion 184
which includes electrically conductive portions or members 186
which are disposed upon top or first surface 187, and several
electrically conductive portions or members 188 which are disposed
upon bottom or second surface 189. In one non-limiting embodiment
of the invention, core portion 184 comprises conventional and
commercially available aluminum material while layers/members 186,
188 comprise conventional, commercially available, and
substantially identical electrically conductive material, such as
copper.
[0045] In the second step of process 180, as shown best in FIG.
4(b) and FIG. 4(d), a pair of dielectric adhesive layers or members
190 and 192 are acquired and/or created. These members 190, 192
respectively have top surfaces 194, 196 and bottom surfaces 198,
200.
[0046] In the third step of process 180, as shown best in FIG.
4(c), a pre-circuit assembly 202 is provided which is generally and
relatively flexible. Particularly, assembly 202 comprises a
substantially and relatively flexible core member or portion 204
having several electrically conductive portions or members 206
which are disposed upon the top or first surface 207 and having
several electrically conductive portions or members 208 which are
selectively disposed upon the second or bottom surface 209.
[0047] In the fourth step of process 180, as shown best in FIG.
4(e), pre-circuit assembly 210 is provided. Particularly,
pre-circuit assembly 210 includes a core member or portion 212
having several electrically conductive portions or members 214
disposed upon a first or top surface 215 and having several
electrically conductive portions or members 216 selectively
disposed upon a second or bottom surface 217. In one non-limiting
embodiment of the invention, core portion 212 comprises
conventional and commercially available aluminum material while
layers/members 214, 216 each comprise conventional, commercially
available, and substantially identical electrically conductive
material, such as copper.
[0048] In the fifth step of process 180, as shown best in FIG.
4(f), members 188 of pre-circuit assembly 182 are operatively
attached or coupled to the top surface 194 of adhesive 190.
Portions 206 of pre-circuit assembly 202 are then operatively
connected and/or coupled to the bottom surface 198 of material 190.
Portions 208 of pre-circuit assembly 202 are coupled to the top
surface 196 of material layer 192. Portions 214 of pre-circuit
assembly 210 is operatively connected and/or coupled to the bottom
surface 200 of material layer 192, forming a pre-circuit assembly
270 which may be processed by drilling, electroplating, and/or any
other process or methodology producing circuit layer
interconnections. It should be appreciated that pre-circuit 270 may
be subjected to a certain etchant material (e.g., and aluminum
etchant material) which "etches away" or removes certain portions
of core metal members 184, 212 and which allows the formed
pre-circuit assembly to be substantially and relatively
flexible.
[0049] It should be appreciated that the pre-circuit assemblies
formed by processes 140, 180 may be constructed and/or otherwise
assembled by the use of multi-layer circuit boards which are formed
prior to the use of processes 140, 180 or by attaching multi-layer
circuit boards formed concomitantly with process 140, 180. It
should further be appreciated that "adhesive" or "non-adhesive"
containing circuit boards and/or circuit board assemblies may be
alternately and selectively used concomitantly with processes 140,
180. In one non-limiting embodiment of the invention, these circuit
boards may be alternately and selectively used to produce circuit
interconnections of the "power" type, the "signal" type, the
"ground plane" type, or the "interconnection" type.
[0050] It should be understood that the invention is not limited to
the exact embodiment or construction which has been illustrated and
described but that various changes may be made without departing
from the spirit and the scope of the invention.
* * * * *