U.S. patent number 3,644,661 [Application Number 05/095,809] was granted by the patent office on 1972-02-22 for double-sided circuit having terminal-receiving portions.
This patent grant is currently assigned to Western Electric Company, Incorporated. Invention is credited to Madhu P. Asar, John E. Bolin, Harry L. Maddox.
United States Patent |
3,644,661 |
Asar , et al. |
February 22, 1972 |
DOUBLE-SIDED CIRCUIT HAVING TERMINAL-RECEIVING PORTIONS
Abstract
A flexible, semirigid substrate, composed of a nonconducting
material, supports a plurality of spaced, longitudinal conductors
on one side thereof and a plurality of parallel, spaced, transverse
conductors on the other side thereof. Through-hole connections are
made through the substrate between selected longitudinal conductors
and selected transverse conductors. The transverse conductors
extend to a common edge of the substrate, which is formed with a
longitudinal fold. The portion of each of the transverse conductors
which extends over the longitudinal fold in the substrate is formed
with an elongated opening which is disposed symmetrically about the
axis of the transverse conductor. The longitudinal opening provides
a saddle for receiving a portion of a terminal which rests in the
saddle and can be subsequently soldered with the transverse
conductor associated with the saddle.
Inventors: |
Asar; Madhu P. (Columbus,
OH), Bolin; John E. (Greensboro, NC), Maddox; Harry
L. (Columbus, OH) |
Assignee: |
Western Electric Company,
Incorporated (New York, NY)
|
Family
ID: |
22253679 |
Appl.
No.: |
05/095,809 |
Filed: |
December 7, 1970 |
Current U.S.
Class: |
174/261; 174/255;
439/77; 361/751; 361/775 |
Current CPC
Class: |
H05K
3/3405 (20130101); H05K 7/08 (20130101); H05K
3/326 (20130101); H05K 2201/0367 (20130101); H05K
3/403 (20130101); H05K 1/0289 (20130101); H05K
2201/1034 (20130101); H05K 2201/096 (20130101); H05K
1/118 (20130101); H05K 3/3447 (20130101); H05K
3/306 (20130101); H05K 2201/091 (20130101); H05K
2201/055 (20130101) |
Current International
Class: |
H05K
3/32 (20060101); H05K 7/08 (20060101); H05K
3/34 (20060101); H05K 7/02 (20060101); H05K
3/30 (20060101); H05K 1/11 (20060101); H05K
1/00 (20060101); H05K 3/40 (20060101); H05k
001/18 () |
Field of
Search: |
;174/68.5,88R
;317/11R,11C,11CC,11CM,11CE,11CW,11D ;339/275,275B,17 ;335/112
;29/628,626 |
Foreign Patent Documents
Other References
Feth, "Interconnection Means For Circuit Modules," IBM Technical
Disclosure Bulletin, Vol. 7, No. 6, Nov. 1964, pp. 469,
470..
|
Primary Examiner: Clay; Darrell L.
Claims
We claim:
1. A double-sided circuit which comprises:
a substrate composed of a nonconductive material;
at least a pair of conductive paths supported on one side of a
substrate;
at least one conductive path supported on a side of the substrate
opposite from the one side;
the one conductive path being connected to each of the pair of
conductive paths to connect the pair of conductive paths together;
and
at least portions of each of the pair of conductive paths supported
on the substrate being formed with a saddle having a depression
contoured to receive at least portions of terminations of external
circuits to facilitate interconnecting of the terminations, the
contoured depression of the saddle being spaced from the connection
of the one conductive path and the pair of conductive paths.
2. The double-sided circuit as set forth in claim 1, wherein the
pair of conductive paths are supported in their entirety upon the
one side of the substrate.
3. The double-sided circuit as set forth in claim 1, wherein the
substrate is formed from polyimide material.
4. The double-sided circuit as set forth in claim 1, wherein
portions of the substrate which include at least portions of the
pair of conductive paths are formed with a fold whereat the saddles
of the pair of conductive paths are located so that the saddles are
prominently positioned for assembly with external terminations.
5. The double-sided circuit as set forth in claim 1, which further
comprises an insulating material placed over the portions of the
pair of conducting paths exclusive of the saddles and over the one
conducting path.
6. The double-sided circuit as set forth in claim 1, wherein the
substrate is flexible.
7. A double-sided circuit which comprises:
a substrate composed of a nonconductive material which is at least
semirigid;
a first plurality of spaced, parallel conductors supported on one
side of the substrate;
a second plurality of spaced, parallel conductors supported on the
opposite side of the substrate;
selected conductors of the first plurality on the one side of the
substrate being connected to selected conductors of the second
plurality on the opposite side of the substrate;
the second plurality of conductors being arranged on the substrate
in a connecting relationship with the first plurality of conductors
to interconnect selected conductors of the first plurality;
at least portions of the substrate which support the first
plurality of conductors thereon being formed with a fold which
positions portions of the first plurality of conductors in a planar
displacement from remaining portions of the conductors, and
a nest formed in each of the first plurality of conductors in the
displaced portion thereof to receive and engage a termination of an
external circuit.
8. The double-sided circuit as set forth in claim 7, wherein the
nonconductive material of the substrate is polyimide.
9. The double-sided circuit as set forth in claim 7, wherein the
first plurality of conductors are of the type which are deposited
on, supported by and conform to the shape of the underlying
portions of the substrate.
10. The double-sided circuit as set forth in claim 7, wherein the
nest of each of the first plurality of the conductors includes an
opening formed in the displaced portion of each of the conductors
on the fold of the substrate.
11. The double-sided circuit as set forth in claim 7, wherein the
first plurality of conductors is divided into groups of conductors
extending transversely of the substrate and the second plurality of
conductors extend longitudinally of the substrate with each of the
conductors of the second plurality being connected selectively to
at least one conductor in each of the group of conductors to
interconnect selected conductors of different groups.
12. The double-sided circuit as set forth in claim 7, wherein an
insulating material is placed over the first and second plurality
of conductors exclusive of the portions of the conductors which
include the nests.
13. An electrical device having circuit portions which
comprises:
a plurality of terminals extending from the device and connected to
the circuit portions of the device;
a double-sided circuit including:
a substrate composed of a nonconductive material which is at least
semirigid,
a first plurality of spaced, parallel conductors supported on one
side of the substrate,
a second plurality of spaced, parallel conductors supported on the
opposite side of the substrate,
selected conductors of the first plurality on the one side of the
substrate being connected to selected conductors of the second
plurality on the opposite side of the substrate,
the second plurality of conductors being arranged on the substrate
in a connecting relationship with the first plurality of conductors
to interconnect selected conductors of the first plurality,
at least portions of the substrate which support the first
plurality of conductors thereon being formed with a fold which
positions portions of the first plurality of conductors in a planar
displacement from remaining portions of the conductors, and
a nest formed in each of the first plurality of conductors in the
displaced portion thereof; and
each of the terminals having at least portions thereof positioned
in the nest of one of the first plurality of conductors and secured
thereto to interconnect selected terminals thereby.
14. The electrical device as set forth in claim 13, wherein the
device is a crossbar switch.
15. The electrical device as set forth in claim 13 which further
comprises:
the terminals which extend from the device being arranged in at
least one row containing a plurality of groups of terminals;
the first plurality of conductors being divided into groups of
conductors extending transversely of the substrate and the second
plurality of conductors extending longitudinally of the substrate
with each of the conductors of the second plurality being connected
selectively to at least one conductor in each of the groups of
conductors, and
selected terminals of each group in the row being connected to
selected conductors of the first plurality of conductors to
interconnect each selected terminal of one group with at least one
other selected terminal in another group through the
interconnecting relationship of the first and second plurality of
conductors.
16. The electrical device as set forth in claim 13, wherein an
insulating material is placed over the first and second plurality
of conductors exclusive of the portions of the conductors which
include the nests.
17. A double-sided circuit which comprises:
a substrate composed of a nonconductive material;
at least a pair of conductive paths supported on one side of the
substrate;
at least one conductive path supported on a side of the substrate
opposite from the one side;
the one conductive path being connected to each of the pair of
conductive paths to connect the pair of conductive paths
together;
at least portions of each of the pair of conductive paths supported
on the substrate being formed with a saddle upon which at least
portions of terminations of external circuits can rest to
facilitate interconnecting of the terminations;
at least portions of the substrate which include at least portions
of the pair of conductive paths formed with a fold whereat the
saddles of the pair of conductive paths are located so that the
saddles are prominently positioned for assembly with external
terminations; and
at least a portion of each of the pair of conductive paths which
form the saddle formed with an opening to provide the saddle on the
fold of the substrate.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to double-sided circuits having
terminal-receiving portions and more particularly relates to
double-sided circuits having terminal-receiving portions formed
therein for easy assembly with associated terminals and subsequent
securing of the circuit with the terminals.
2. Description of the Prior Art
In the manufacture of various types of electrical equipment, a
multitude of terminals extend from a common surface of such devices
and require interconnections between selected terminals to
facilitate the subsequent operation of the device. In many
instances the devices are relatively small and the spacing in any
direction between adjacent terminals is extremely small. Due to the
density of the terminals extending from the one surface of the
device, it is a somewhat tedious and difficult operation for an
operator or a machine to apply and secure interconnecting
conductors between selected terminals of the device which must be
interconnected to facilitate the subsequent operation of the
device.
An example of an electrical device requiring interconnecting wiring
is an electrical communications switch, such as a crossbar switch.
In the past, the conventional crossbar switch has been of
sufficient size to permit interconnecting conductors and wiring
between selected terminals of the switch to be assembled and
secured with the switch with little difficulty.
Recently a new and improved crossbar switch was developed which is
considerably smaller than the conventional crossbar switch. The
smaller crossbar switch is disclosed in U.S. Pat. No. 3,445,795,
which was issued to R. P. Holtfreter and H. E. McCullough on May
20, 1969. The compactness of the newly designed crossbar switch
permits a reduction in the amount of space required to accommodate
a switch of this type in its ultimate environment, for example, in
a telephone central office. With the smaller switch, more switches
can be installed in available mounting equipment, thus reducing the
expenses of switch users.
However, with the influx of smaller devices, such as the newly
developed crossbar switch, it is necessary to confine the
terminating areas of the switch to a smaller area compared to the
conventional crossbar switch. Since the terminals which extend from
one surface of the small crossbar switch are extremely close to
adjacent terminals, it is extremely difficult for an operator to
interconnect selected terminals using existing procedures and
techniques. For example, the crowded display of terminals extending
from the terminating area of the newly developed switch does not
easily facilitate the maneuvering of individual conductors into the
areas of the terminals and the subsequent positioning of securing
means, such as solder and a soldering device, into the confined
spaces between the terminals being secured to the conductor.
Consequently, it became obvious that new techniques and
interconnecting facilities had to be developed in order to provide
a small crossbar switch which would not be hampered by a high cost
imposed upon the ultimate switch because of a tedious and
time-consuming interconnecting of selected terminals of the
switch.
SUMMARY OF THE INVENTION
It is, therefore, an object of this invention to provide a new and
improved double-sided circuit which can be utilized to interconnect
selected terminals in an area of high terminal density.
Another object of this invention is to provide a new and improved
double-sided circuit having terminal-receiving portions which
facilitate the easy assembly and securing of the circuit with
closely spaced terminals in an area of high terminal density.
Still another object of this invention is the provision of a new
and improved double-sided circuit which is relatively thin and
semirigid to permit the circuit to be inserted between closely
spaced rows of terminals and assembled with terminals of one row
for interconnecting selected terminals within the row.
A further object of this invention is the provision of a new and
improved double-sided circuit having terminating conductors formed
with saddlelike openings for assembly and securing with closely
spaced terminals of an electrical device to interconnect selected
ones of the terminals.
A double-sided circuit illustrating certain features of the
invention may include a nonconductive substrate having at least one
bus conductor on one side thereof and a plurality of terminating
conductors on the other side thereof which are interconnected
through connection to the bus conductor. Each of the terminating
conductors is formed with means for receiving and engaging a
portion of an associated terminal so that all terminals in
engagement with the terminating conductors are interconnected
through the terminating conductors and the bus conductor.
BRIEF DESCRIPTION OF THE DRAWINGS
Other objects and features of the present invention will be more
readily understood from the following detailed description thereof
when read in conjunction with the accompanying drawings, in
which:
FIG. 1 is a partial perspective view of an electrical device such
as a small crossbar switch showing an area of high terminal density
on one side of the switch;
FIG. 2 is a plan view of a double-sided circuit embodying certain
principles of the invention;
FIG. 3 is a sectional view, taken along line 3--3 of FIG. 2,
showing a cross section of the circuit with a terminal of an
electrical device, shown in phantom view, being assembled with the
circuit;
FIG. 4 is a perspective view showing a plurality of double-sided
circuits assembled with terminals extending from the electrical
device of FIG. 1, and
FIG. 5 is a partial perspective view showing a terminal assembled
and secured within a saddle portion of a conductor of a
double-sided circuit.
DETAILED DESCRIPTION
Referring to FIG. 1, there is illustrated in partial view an
electrical device, such as a small crossbar switch, designated
generally by the reference numeral 11. The switch 11 is of the type
described and claimed in the aforementioned U.S. Pat. No.
3,445,795. A plurality of terminals 12--12 extend from a rather
confined area of one side of the switch and are connected to
circuit portions of the switch, such as switching contacts, to
provide interconnections between the circuit portions and external
circuits. As an example of one type of crossbar switch 11 having
such a high terminal density, the terminals are arranged in spaced
rows with each terminal in each row being spaced 0.209 inch from
adjacent terminals in the same row. Each row of terminals is 0.220
inch from adjacent rows of terminals. In one type of the crossbar
switch 11 which has a high terminal density, there are 20 groups of
six terminals 12--12 each for a total of 120 terminals in each row,
and there are 12 rows of terminals. Generally, 1,440 terminals
extend from an area which measures approximately 25 inches by 21/2
inches.
In the ultimate operation of the switch 11, it is necessary to
connect each terminal 12 of each group within a given row of the
terminals with its corresponding terminals in the remaining groups
in the same row. Thus it is readily seen that, in view of the high
density of the terminals 12--12, it would be a tedious and
time-consuming operation to assemble conventional wiring with the
terminals to be interconnected and further to secure the conductors
with the terminals. For example, if conventional wiring was
utilized, the wiring would have to be placed at varying depths
within the maze of terminals 12--12 in order to avoid crossover
connections. Further, sufficient space would have to be provided at
the free ends of the terminals 12--12 to facilitate connection,
such as wire-wrapped connections, from the terminals to external
circuits. It became obvious during the development of the small
crossbar switch 11 that some means had to be developed which would
facilitate an easy and relatively quick interconnecting of the
selected terminals 12--12 in order to maintain the ultimate switch
at a reasonable cost.
Referring now to FIG. 2, there is illustrated a double-sided,
flexible, substantially flat, semirigid, printed circuit,
designated generally by the numeral 13. The printed circuit 13
includes a substrate 14, which is flexible and which is composed of
a nonconductive material, such as a polyimide film. In the
particular embodiment of the double-sided printed circuit 13
illustrated in FIG. 2, six longitudinal, spaced, parallel, bus
conductors 16--16 are supported on one side of the substrate 14 and
extend the entire length of the substrate.
A plurality of groups 17A through 17L of terminating conductors
18--18 are secured to the opposite side of the substrate 14 and
extend generally in a transverse direction between opposite
longitudinal edges 19 and 21 of the substrate. In examining the
arrangement of the terminating conductors 18--18 of the group 17A,
it is observed that the leftmost conductor extends substantially
across the entire width of the substrate 14 and the rightmost
conductor extends from the longitudinal edge 19 toward the
longitudinal edge 21 but only for a short distance. The remaining
terminating conductors 18--18 extend varying distances from the
edge 19 of the substrate 14 toward the edge 21 thereof. The
remaining groups 17B through 17L of the terminating conductors
18--18 are arranged in a similar fashion.
Each leftmost terminating conductor 18 of the groups 17A through
17L are connected to the uppermost bus conductor 16 by through-hole
connections, indicated by the circles 22--22. By utilization of the
through-hole connections 22--22, each leftmost terminating
conductor 18 of the groups 17A through 17L are thereby
interconnected with the leftmost terminating conductors of the
other groups of terminating conductors. The remaining terminating
conductors 18--18 of each of the groups 17A through 17L are
connected in a similar fashion so that each terminal 12 of each
group of six terminals in a given row is connected to its
corresponding terminal in the remaining groups of terminals.
It is noted that the bus conductors 16--16 and the terminating
conductors 18--18 can be secured with the substrate 14 in any
manner, such as, for example, by depositing positively the
conductive material onto the substrate in a defined pattern. In
addition, in one embodiment of the invention, the substrate 14 can
be composed of any suitable nonconductive material, such as a
polyimide film, which is sufficient to provide a flexible but
semirigid support for the conductors 16--16 and 18--18. In another
embodiment of the invention, the substrate 14 could be rigid. For
example, the substrate 14 could include a metal sheet having an
insulating-material coating. While the illustrated example of the
switch 11 is shown with six terminals 12--12 in each of the groups
17A through 17L, it is to be understood that each group could
contain any number of terminals other than six and not depart from
the spirit and scope of the invention.
Subsequent to the securing of the conductors 16--16 and 18--18 with
the substrate 14, an elongated opening 23 is punched and formed in
each of the terminating conductors 18--18 at a location which is
adjacent to the end of the conductor which terminates adjacent to
the edge 19 of the substrate 14, as illustrated in FIG. 2, which
edge is common to all of the terminating conductors. The opening 23
could also continue through the substrate 14. As viewed in FIGS. 2
and 3, a longitudinal portion of the substrate 14, which is
adjacent to the edge 19, and which includes the elongated openings
23--23, is formed with a longitudinal fold 24. The fold 24 in the
substrate 14 provides a humplike configuration near the edge 19 of
the substrate so that each of the elongated openings 23 are formed
to provide a saddle, designated generally by the numeral 26, to
receive a corresponding one of the terminals 12--12 of the crossbar
switch 11. The saddle 26 provides a nest which is thereby
positioned in planar displacement from the remaining portions of
the terminating conductors 18--18.
Thereafter a nonconducting film 27, which could be flexible, is
placed over the longitudinal bus conductors 16--16, and is
adhesively bonded to the conductors and the adjacent portion of the
substrate 14 to insulate the bus conductors from external elements.
In addition, a longitudinal nonconductive film 28, which could be
flexible, is positioned over portions of the terminating conductors
18--18, leaving the saddles 26--26 exposed to insulate the portions
of the terminating conductors from external elements.
Referring now to FIG. 3, there is illustrated a cross section of
the double-sided circuit 13, taken along line 3--3 of FIG. 2. Also
illustrated in phantom view is one terminal 12 extending from the
switch 11 with an intermediate portion of the terminal being
positioned within the saddle 26. It is noted that the saddle 26
does not provide an opening wherein the terminal 12 passes through
the circuit, but rather provides a nesting facility onto which the
intermediate portion of the associated terminal is positioned. This
permits an easy and fast assembly of the double-sided circuit 13
with a selected row of the terminals 12--12.
In an assembly procedure, the circuit 13 is inserted into a
position beneath the selected row of terminals 12--12. Thereafter
any one of the saddles 26--26 of the circuit 13 is visibly aligned
with the associated terminal 12 and the circuit moved upwardly so
that all of the saddles of the circuit move into engagement with
adjacent portions of the associated terminals.
If an apertured configuration in a printed circuit had been
utilized, the alignment and insertion procedure of the circuit with
the terminals would be a difficult procedure in view of the
position of the apertures of the circuit relative to the free ends
of the terminals and the high terminal density of the
terminals.
Referring now to FIG. 4, a first one of the double-sided circuits
13--13 is positioned beneath the lowermost row of terminals 12--12
with longitudinal edge 21 of the circuit being positioned
substantially adjacent to the portion of the switch 11 from which
the terminals extend. After the double-sided circuit 13 has been
positioned beneath the lowermost row of terminals 12--12, the
circuit is manipulated to align the leftmost terminating conductor
18 of the circuit with the leftmost terminal 12 of the switch 11 in
the lowermost row. The terminating conductors 18--18 of the
double-sided circuit 13 have been placed on the substrate 14 in a
parallel and spaced fashion with the centerline spacing between the
terminating conductors being equal to the centerline spacing
between the terminals in any row. Thus, the terminating conductors
18--18 are now aligned with associated terminals 12--12 with which
they are to be assembled and secured. The circuit 13 is then raised
so that portions of each of the terminals 12--12 are engaged by the
saddle 26 of the associated terminating conductors 18--18.
As illustrated in FIG. 5, after the portions of the terminals
12--12 have been positioned in the associated saddles 26--26 of the
associated terminating conductors 18--18, an operator applies
molten solder 29 into the area of each saddle so that, when the
solder solidifies, each terminal is not only electrically connected
but is also firmly secured with the associated terminating
conductor. Since the circuit 13 is lightweight, the soldered areas
of each saddle 26 and terminal 12 are sufficient to provide the
only means by which the circuit is firmly secured with the switch
11.
Since the saddles 26--26 of the terminating conductors 18--18 of a
given circuit 13 are aligned longitudinally, the soldering
operation of soldering the terminating conductors to the associated
terminals 12--12 of a given row can be accomplished in a relatively
short period of time and with relative ease. This permits an
operator who is performing the soldering operation to move a
soldering device and solder supply in a relatively straight line
along the longitudinal path of the saddles 26--26 adjacent to the
free ends of the terminals 12--12.
Referring again to FIG. 4, the operator then places a second
circuit 13 between the lowermost row of terminals 12--12 and the
next-to-lowermost row of terminals. The aligning and assembling
procedure then follows the same pattern as that outlined in
assembling the circuit 13 with the lowermost row of terminals
12--12. This pattern is followed until each row of terminals 12--12
is assembled and electrically secured with an associated one of the
double-sided printed circuits 13--13.
When the assembly is complete, it is apparent that selected
terminals 12--12 in each row of terminals are interconnected
through the associated terminating conductors 18--18 and the bus
conductors 16--16. For example, in the illustrated switch 11, the
terminals 12--12 are also separated into groups of six terminals
each. With the double-sided circuit 13 being arranged as previously
described in groups 17A through 17L, each terminal 12 of one group
of terminals is interconnected with the corresponding terminal in
each of the other groups of terminals within a given row. This
provides an interconnecting arrangement which is necessary for the
switch 11 to function as intended.
The width of the double-sided printed circuit 13 is sufficient to
permit a substantial free-end portion of the terminal 12 to extend
from the saddles 26--26 after the circuit has been assembled and
secured with the terminals. This substantial free-end portion of
the terminals 12--12 permits subsequent wire-wrap connections to be
made between the terminals and external circuits which utilize the
switching capabilities of the switch 11.
The semirigid nature of the printed circuit 13 permits the operator
to easily manipulate and position the circuits between the closely
spaced rows of terminals 12--12 and to easily align the circuit
with the associated terminals. Additionally, due to the semirigid
feature of the circuit 13, the circuit is easily held during the
soldering of the terminating conductors 18--18 with the associated
terminals 12--12. Further, the semirigid nature of the printed
circuit 13 permits the circuit to maintain a position which is
relatively close to the underside of the row of terminals 12--12 to
which it is assembled and secured, thereby precluding the drooping
of the circuit onto the row of terminals immediately
therebelow.
In view of the semirigid nature of the printed circuit 13, the
outer films 27 and 28 are not necessary to accomplish the intended
purpose of the inventive design of the circuit 13. However, to
prevent the bus and terminating conductors 16 and 18, respectively,
from being connected undesirably to unassociated terminals 12--12
or other elements external of the desired connections, the films 27
and 28 are placed over the conductors in the manner previously
described and as shown in FIGS. 2 and 3.
* * * * *