Field of the Invention
[0001] This invention generally relates to the art of electrical connectors and, particularly,
to methods and structure for controlling the impedance and the inductance in electrical
connectors.
Background of the Invention
[0002] In today's high speed electronic equipment, it is desirable that all components of
an interconnection path be optimized for signal transmission characteristics, otherwise
the integrity of the system will be impaired or degraded. Such characteristics include
risetime degradation or system bandwidth, crosstalk, impedance control and propagation
delay. Ideally, an electrical connector would have little or no affect on the interconnection
system regarding these characteristics. An ideal connector would be "transparent".
In other words, the system would function as if circuitry ran through the interconnection
and there would be no affect on the system whatsoever. However, such an ideal connector
is impractical or impossible, and continuous efforts are made to develop electrical
connectors which have as little affect on the system as possible.
[0003] Impedance and inductance control are concerns in designing an ideal connector. This
is particularly true in electrical connectors for high speed electronic equipment,
i.e. involving high frequencies. An example of such connectors is the popular type
of electrical connector commonly called an "edge card" connector. An edge card connector
is provided for receiving a printed circuit board having a mating edge and a plurality
of contact pads adjacent the edge. Such edge connectors have an elongated housing
defining an elongated receptacle or slot for receiving the mating edge of the printed
circuit board. A plurality of terminals are spaced along one or both sides of the
slot for engaging the contact pads adjacent the mating edge of the board. In many
applications, such edge connectors are mounted on a second printed circuit board.
The mating "edge" board commonly is called the "daughter" board, and the board to
which the connector is mounted is called the "mother" board.
[0004] This invention is directed to a method and structure for tuning the impedance of
an electrical connector, such as an edge connector, for interconnection in an electrical
circuit having a given impedance and tuning the connector to substantially match that
impedance. The invention also is directed to providing terminals for printed circuit
board mounted connectors which reduce the inductance of the connectors.
Summary of the Invention
[0005] An object, therefore, of the invention is to provide a method and structure for tuning
the impedance of an electrical connector adapted for interconnection in an electrical
circuit having a given impedance.
[0006] Another object of the invention is to provide improved terminals for reducing the
inductance of an electrical connector, particularly a connector mounted to a printed
circuit board.
[0007] In the exemplary embodiment of the invention, generally, the connector includes a
dielectric housing for mounting a plurality of terminals, the housing having a receptacle
for receiving a complementary mating connector. Specifically, the invention is illustrated
in an edge connector having a slot for receiving the mating edge of a printed circuit
board.
[0008] The invention contemplates a method and structure of providing the terminals with
body portions located in the housing and contact portions located at the receptacle
or slot for engaging appropriate terminals of the mating connector or printed circuit
board when inserted into the receptacle or slot. The area of the body portions of
the terminals is selectively varied to selectively vary the capacitance of the terminals
and, therefore, the impedance of the connector to match the given impedance of the
electrical circuit.
[0009] The area of the body portions of the terminals may be varied by varying the overall
size of the body portions. The body portions of the terminals may be provided of constant
widths mountable in uniformly sized recesses in the housing, and the area of the body
portions may be varied by varying the lengths thereof. Further, the body portions
of the terminals may be provided of a uniform overall size mountable in uniformly
sized recesses in the housing, and the area of the body portions may be varied by
forming openings therein.
[0010] In the illustrated embodiment of the invention, i.e. in an edge connector, the body
portions of the terminals are provided as mounting barbs press fit into recesses in
the housing for securing the terminals in the housing. The terminals are provided
with base portions, the contact portions and the mounting barbs projecting from the
base portions.
[0011] The invention also contemplates an electrical connector for mounting on a printed
circuit board having a common ground circuit and a plurality of circuit traces forming
portions of the common ground circuit. The connector has a plurality of signal terminals
and a plurality of ground terminals mounted in the housing. At least one of the ground
terminals has at least two grounding feet for engaging a respective one of the circuit
traces of the common ground circuit to establish a multiple-point contact therewith.
[0012] Other objects, features and advantages of the invention will be apparent from the
following detailed description taken in connection with the accompanying drawings.
Brief Description of the Drawings
[0013] The features of this invention which are believed to be novel are set forth with
particularity in the appended claims. The invention, together with its objects and
the advantages thereof, may be best understood by reference to the following description
taken in conjunction with the accompanying drawings, in which like reference numerals
identify like elements in the figures and in which:
FIGURE 1 is a perspective view, partly in section, of an electrical connector in which
the invention is applicable;
FIGURE 2 is a vertical section through the elongated electrical connector of Figure
1;
FIGURE 3 is a vertical section similar to Figure 2 but showing the long terminals;
FIGURE 4 is a vertical section similar to that of Figure 2, but with the width of
the barb of the terminal increased;
FIGURE 5 is a vertical section similar to that of Figure 3, but with the width of
the barb increased;
FIGURE 6 is a vertical section similar to that of Figure 2, but with the length of
the barb shortened;
FIGURE 7 is a vertical section similar to that of Figure 4, but with the area of the
barb reduced by providing openings therein; and
FIGURE 8 is a graph showing impedance characteristics of an electrical circuit versus
possible impedance characteristics of an electrical connector.
Detailed Description of the Preferred Embodiment
[0014] Referring to the drawings in greater detail, and first to Figure 1, the invention
is embodied in an edge connector, generally designated 10, for a printed circuit board
(not shown) having a mating edge and a plurality of contact pads adjacent the edge.
These types of connectors commonly are called "edge card" connectors in that they
have receptacle means in the form of a slot 12 for allowing insertion of a printed
circuit board into a contact area of the connector, usually under low insertion force
conditions. Such connectors normally are elongated and have rows of spring contact
elements, generally designated 14 in Figure 1, spaced along one or both sides of slot
12 lengthwise of a dielectric housing 16. The spring contact elements engage contact
pads spaced along a mating edge of the printed circuit board which is inserted into
the slot. It should be understood that the concepts of the invention are not limited
to edge connectors of the character described, and the invention can be embodied in
a wide variety of applicable electrical connectors.
[0015] With this understanding, dielectric housing 16 of edge connector 10 includes a plurality
of standoffs 18 depending from the housing for engaging a surface of a second printed
circuit board. Often, the second printed circuit board is called a "mother board",
and the printed circuit board which is inserted into slot 12 is called a "daughter
board". Dielectric housing 16 also includes a plurality of mounting or retention pegs
(not shown) for locating the connector on the mother board by inserting the pegs into
mounting holes in the board.
[0016] Referring to Figures 1-3, housing 16 includes a plurality of transverse cavities,
generally designated 22, spaced longitudinally of slot 12 for receiving alternating
differently configured terminals, as described below. Specifically, each cavity 22
has a cavity portion 22a on one side of slot 12 (the left-hand side as viewed in Figures
2 and 3) and a cavity portion 22b on the opposite of the slot (the right-hand side
as viewed in Figures 2 and 3). Cavities 22 are separated lengthwise of the elongated
housing by wall means or partitions which include wall portions 24a separating cavity
portions 22a and wall portions 24b separating cavity portions 22b.
[0017] Lastly, housing 16 includes a plurality of recesses or holes 26 outside cavities
22 and generally in transverse alignment therewith, for purposes described below.
Each recess or hole 26 includes a lower mouth 26a opening at the bottom of housing
16. The entire housing is unitarily molded of dielectric material such as plastic
or the like.
[0018] Generally, a plurality of terminals are mounted on housing 16, spaced longitudinally
of the housing and corresponding to the plurality of transversely aligned cavities
22 and holes 26. Before describing the terminals in detail, it should be understood
that the printed circuit board (i.e. the daughter board) which is inserted into slot
12 often has a plurality of contact pads defining two rows of pads along the edge
of the board, i.e. the mating edge which is inserted into the slot. One row of contact
pads is located near the absolute edge of the board, and the other row of contact
pads is spaced inwardly from the one row. Therefore, conventionally, terminals are
located on housing 16 with contact elements alternating lengthwise of the housing
for alternatingly engaging the contact pads in the two rows thereof along the mating
edge of the printed circuit board.
[0019] More particularly, terminals, generally designated 28 and 30, are mounted on housing
16 in an alternating array lengthwise of the housing. In other words, terminals 28
alternate between adjacent terminals 30. Both configurations of terminals are similar
to the extent that they have base portions 32, body portions 34 projecting upwardly
from the base portions and contact feet 36 projecting downwardly from the base portions.
Body portions 34 are provided in the form of barbs for mounting the terminals on housing
16 by inserting the barbs through mouths 26a of holes 26 from the bottom of the housing.
Contact feet 36 engage circuit traces on a top surface 38 of a printed circuit board
40 (the mother board). Terminals 28 have cantilevered spring contact elements 42 projecting
upwardly from their respective base portions 32, and terminals 30 have cantilevered
spring contact elements 44 projecting upwardly from their respective base portions.
It is anticipated that terminals 28 will be utilized for the transmission of data
signals at high speeds and terminals 30 will be utilized as part of ground or power
circuits.
[0020] It can be seen in Figure 2 that spring contact element 42 of terminal 28 is shorter
than spring contact element 44 of terminal 30. These differentials in length enable
the alternating terminals to engage the two rows of contact pads on the daughter board,
as described above. It can be seen that spring contact elements 42 and 44 extend into
slot 12 beyond a datum plane 41 which, in the illustrated embodiment, is the left-hand
side of slot 12. Generally, biasing means are provided for biasing the mating edge
of the daughter printed circuit board against datum plane 41, thereby deflecting spring
contact elements 42 and 44 in the direction of arrows "A".
[0021] The stated differentials in length also enable these terminals to be selectively
applied to either ground or signal functions thereby optimizing the connector performance.
The shorter terminal 28 has a shorter spring contact element 42 which results in a
reduced electrical path length from the point of contact of the daughter board to
the mother board, which results in a reduction of the series inductance of the terminal
which thus permits higher speed operation. The longer terminal 30 has a longer contact
element 44 which could be used as a ground terminal which would provide substantial
electrostatic isolation of interposed signal terminals.
[0022] More particularly, still referring to Figures 2 and 3, alternating terminals 30 have
base portions which project transversely across the respective cavities 22, as indicated
at 46, with a spring arm 48 projecting upwardly into cavity portion 22b, and with
a spring element 50 projecting upwardly into slot 12 from the side of the slot opposite
datum plane 41. Therefore, when the daughter printed circuit board is inserted into
slot 12, in the direction of arrows "B", spring elements 50 will bias the board in
the direction of arrows "A", against datum plane 41 and deflecting spring contact
elements 42 and 44 a pre-determined and constant amount.
[0023] In addition, spring element 50 may provide a redundant electrical contact path which
could be used to further reduce contact inductance. This would typically be designated
a ground terminal since one would generally not want a signal terminal to be exposed
for possible capacitive coupling to other signal terminals over such a long path length.
[0024] The invention contemplates a method and structure for tuning the impedance of electrical
connector 10 which is interconnected in an electrical circuit having a given impedance.
With connector 10 being an edge connector, the electrical circuit would be defined
by the circuitry on the printed circuit boards. As stated in the "Background", above,
an ideal connector would be "transparent" in order to have as little effect on the
interconnection as possible. Therefore, the invention is directed to concepts for
"tuning" or varying the impedance of electrical connector 10 to match the given impedance
of the interconnection system or the electrical circuit in which the connector is
interconnected.
[0025] The given impedance often is called the "characteristic" impedance of a circuit and
usually is known. For instance, a manufacturer of electrical connectors often is supplied
by a customer with a characteristic impedance value of the circuit within which the
customer is going to interconnect the particular connector. Even if this situation
is not present, the impedance of any circuit can be measured by various means, such
as a time domain reflectometer which utilizes an electric analog to a radar system,
as well as other measuring or analyzing devices. The impedance of any particular connector
similarly can be measured from input to output, again by using such instruments as
a time domain reflectometer. If the impedance of the connector does not match the
impedance of the interconnecting circuit, the invention contemplates a method and
structure for tuning or varying the impedance of the connector in order to match the
impedance of the interconnecting circuit as close as possible.
[0026] Specifically, reference is made to Figures 4 and 5 wherein like reference numerals
have been applied to like components described in relation to the above description
of Figures 2 and 3. It can be seen in Figures 4 and 5 that body portions or barbs
34' of terminals 28 and 30 are larger in area than barbs 34 shown in Figures 2 and
3. Barbs 34' are mounted in enlarged recesses or holes 26' in the connector housing.
Basically, in the embodiment of the invention shown in Figures 4 and 5, barbs 34'
are of the same length but wider than barbs 34 in the embodiment illustrated in Figures
2 and 3. As will be described in greater detail hereinafter, by selectively varying
the area of body portions or barbs 34, 34' of the terminals, the capacitance of the
terminals is selectively varied and, therefore, the impedance thereof can be changed
to substantially match the given impedance of the electrical circuit in which the
terminals and/or connector are interconnected.
[0027] Figure 6 shows another embodiment to illustrate an alternate method/structure for
varying the body portions or barbs of terminals 28 and 30. Specifically, it can be
seen that barb 34'' for terminal 28 in Figure 6 is the same width as barb 34 in Figure
1. However, barb 34'' is shorter than barb 34 and, consequently, the area thereof
is varied which, in turn, varies the capacitance of the terminals and, therefore,
the impedance thereof. With the embodiment of Figure 6, housing 16 can be fabricated
with constant sized recesses or holes 26 and only the configurations of terminals
28 and 30 need to be varied.
[0028] Similarly, Figure 7 can be compared to Figure 4 wherein it can be seen that a barb
34''' is provided of the same length and width as barb 34' in Figure 4. However, in
the embodiment of Figure 7, the area of body portion or barb 34''' is varied by forming
openings 60 in the barb. Therefore, again, a housing can be fabricated with a constant
width recess or hole 26', and only the configuration of the barb needs to be varied
to tune the impedance of the electrical connector.
[0029] Figure 8 graphically shows how the impedance of the electrical connectors can be
tuned by varying the capacitance of the terminals. In the graph of Figure 8, dotted
line 62 represents a desired impedance of an electrical connector which, ideally,
would be matched to the given impedance of the associated electrical circuit. Line
64 represents an impedance which is, as shown, higher than the desired or given impedance.
In order to reduce the impedance (i.e. lowering line 64), capacitance is added. According
to the concepts of the invention, the effective areas of the body portions 34, 34',
34'', 34''' would be increased to increase the capacitance and, thereby, lower the
impedance, preferably to the desired or given impedance represented by line 62. It
should be understood that lines 64 and 66 represent purely schematic illustrations
of average or lumped constant impedance values, solely for illustration purposes.
In fact, if the graph were plotted from actual measurements, the lines would typically
not be smooth but rather "jagged".
[0030] Conversely, line 66 represents a condition wherein the impedance is too low. Under
these conditions, the capacitance should be reduced in order to increase the impedance
to approach the desired or given impedance represented by line 62. Again, according
to the concepts of the invention, this variance or "tuning" can be accomplished by
reducing the effective area of the body portions of the terminals.
[0031] The invention also contemplates a novel structure for reducing the inductance of
an electrical connector, such as the edge connectors shown in Figures 1-7. In connector
10, terminals 28 and 30 may comprise alternating signal terminals, but some of the
terminals may comprise ground terminals. In fact, all of the "long" terminals 30 could
comprise ground terminals. It is desirable to reduce the inductance of any connector,
but, for the following description, it is assumed that terminals 30 are terminals
which are coupled to ground traces on printed circuit board 40 and their spring elements
50 engage ground contact pads on the edge of the daughter board. The individual ground
traces on board 40 all are part of a common ground circuit, as is found in many edge
connectors. Therefore, it would be desirable to reduce the inductance through these
ground terminals to the common ground circuit.
[0032] More particularly, referring back to Figure 2 (along with Figures 3-7) it can be
seen that terminals 28 and 30, and particularly ground terminals 30, have at least
two feet 36, as described above, for engaging a single circuit trace on top surface
38 of printed circuit board 40. At this point, it should be noted that, although feet
36 are illustrated for surface mounting to a circuit trace on the printed circuit
board, at least one of the feet could comprise a solder tail or pin for insertion
into a hole in the printed circuit board, with the solder tail being electrically
connected to the circuit trace on the board or within a plated-through hole in the
board.
[0033] By providing two feet 36 for a single terminal, it is contemplated that both feet
be electrically coupled to a single circuit trace on the board. Such a construction
provides a larger contact surface with the circuit trace. The larger contact surface
reduces the voltage drop and the increase in cross-sectional area reduces the inductance
between a respective terminal and a single circuit trace on the printed circuit board.
Such a structure is particularly useful in high speed connectors. In the case of one
of the ground terminals, both grounding feet would engage a respective one of a plurality
of ground circuit traces on the printed circuit board, the circuit traces being part
of a common ground circuit. By spacing the feet apart from each other, an area of
the board, between the feet, is left open to facilitate routing various other circuit
traces on the board.
[0034] In addition, the larger contact area also provides an advantage when utilized with
signal terminals in high speed applications. Such increased contact area reduces the
series inductance which thus improves high speed performance.
[0035] It will be understood that the invention may be embodied in other specific forms
without departing from the spirit or central characteristics thereof. The present
examples and embodiments, therefore, are to be considered in all respects as illustrative
and not restrictive, and the invention is not to be limited to the details given herein.
1. An electrical connector (10) for mounting on a printed circuit board (40) having a
common ground circuit and a plurality of circuit traces forming portions of the common,
ground circuit, the connector comprising:
a dielectric housing (16) having a slot (12) for receiving the edge of a mating daughter
board therein, and a plurality of terminal receiving cavities (22) adjacent said slot
for mounting a plurality of signal terminals and a plurality of ground terminals;
and
a plurality of signal terminals (28) and a plurality of ground terminals (30) positioned
in said cavities in an alternating array along one side of said slot, said signal
terminals and said ground terminals each having a base portion (32) with a contact
arm (42, 44) extending therefrom with a contact portion thereon for contacting a pad
on the mating daughter board the contact arm of said signal terminals being shorter
than the contact arm of said ground terminals, said signal terminal having at least
one tail portion (36) for mounting to circuit traces on the circuit board and said
ground terminals each having at least two spaced apart tail portions (36) for electrical
and mechanical interconnection to the circuit traces that form portions of the common
ground circuit.
2. A method of tuning the impedance of an electrical connector according to claim 1 adapted
for interconnection in a plurality of electrical circuits, each having a given impedance,
said method comprising the steps of:
providing a set of dielectric electrical connector housings (16) for mounting a plurality
of terminals therein, all of the housings including a substantially identical receptacle
(12) for receiving a complementary mating electrical component, a plurality of
terminal receiving cavities (22) positioned adjacent said receptacle and adapted for
receiving a portion (42, 44) of a terminal therein, and a plurality of anchoring regions
(26), each anchoring region being adapted to receive an anchoring portion (34, 34',
34'', 34''') of a terminal therein to operatively secure said terminal in said housing,
at least some of the housings including anchoring regions different from the anchoring
regions of at least some other of said housings for receiving differently configured
anchoring portions of the terminals;
providing sets of conductive terminals (28, 30) for selective mounting in the set
of housings, all of the terminals having a connection interface section (42, 44),
a tail portion (36) for interconnecting said terminal to its respective electrical
circuit and an anchoring portion (34, 34', 34'', 34''') separate from said connection
interface section, said connection interface sections being substantially identical
and including a contact arm and a contact portion located thereon, each set of terminals
having generally planar anchoring portions of a different surface area than the anchoring
portions of the other sets of terminals in order to vary the impedance characteristics
of each set of terminals;
selecting a set of said terminals in order to select terminals having a desired predetermined
impedance substantially similar to said given impedance without varying the dimensions
of said connection interface sections;
selecting one of said housings having anchoring regions dimensioned for operatively
receiving the anchoring portions of said selected set of terminals thereat; and
inserting said selected set of terminals into said housing.
3. The method of claim 2 wherein the generally planar anchoring portions (34, 34'') of
some of the sets of terminals have a generally identical width and the terminals of
each of said some of the sets have different height in the direction of insertion
into the housing, whereby the terminals of said some of the sets are insertable into
the same housing.
4. The method of claim 2 or 3 wherein said contact arm and said anchoring portion each
extend in a cantilevered manner from a base portion and are spaced apart thereon.
5. The method of claim 4 wherein said anchoring portions are barbs that are press fit
into cavities in said anchoring region.
6. The method of claim 2 wherein the generally planar anchoring portions (34''') of at
least one of said sets of terminals have openings (60) therein to reduce the surface
area of the anchoring portions.
7. A method of tuning the impedance of an electrical connector according to claim 1 adapted
for interconnection in a plurality of electrical circuits, each circuit having a given
impedance, said method comprising the steps of:
(a) providing dielectric electrical connector housing (16) for mounting a plurality
of terminals therein, said housing including a receptacle (12) for receiving a complementary
mating electrical component, a plurality of terminal receiving cavities (22) adjacent
said receptacle adapted for receiving a portion (42, 44) of a terminal therein, and
a plurality of anchoring regions (26) adapted to receive an anchoring portion (34,
34', 34'', 34''') of a terminal therein to operatively secure said terminal in said
housing;
(b) providing sets of conductive terminals (28, 30) for selective mounting in the
housing, all of the terminals having a connection interface section (42, 44), a tail
portion (36) for interconnecting said terminal to one of said electrical circuits
and a body section distinct from said connection interface section and having an anchoring
portion (34, 34', 34'', 34''') thereon to retain said terminal to said housing, said
connection interface sections being substantially identical including a compliant
contact portion for contacting a respective electrical component of said complementary
mating electrical component, each set of terminals including generally planar body
sections having a different surface area than the body sections of the terminals of
the other sets of terminals in order to vary the impedance characteristics of each
set of terminals;
(c) selecting a terminal from one of said sets of terminals in order to select a terminal
having a desired predetermined impedance substantially similar to the given impedance
of a particular electrical circuit without varying the dimensions of said connection
interface sections;
(d) inserting said selected terminal into said housing; and
(e) repeating steps (c) and (d) until terminals are inserted into all of the terminal
receiving cavities of the housing.
8. The method of claim 7 wherein the generally planar body sections of said sets of terminals
have a generally identical width and the body sections of the terminals of each set
have a different height in the direction of insertion into the housing.
9. The method of claims 7 or 8 wherein said contact arm and said anchoring portion each
extend in a cantilevered manner from a base portion and are spaced apart thereon.
10. The method of claims 7, 8 or 9 wherein said anchoring portions are barbs that are
press fit into cavities in said anchoring region.
11. The method of claims 7 to 10 wherein the generally planar body sections of at least
one of said sets of terminals have openings (60) therein to reduce the surface area
of body sections.
12. A method of tuning the impedance of an electrical connector according to claim 1 adapted
for interconnection in a plurality of electrical circuits, each circuit having a given
impedance, said method comprising the steps of:
(a) providing a dielectric electrical connector housing (16) for mounting a plurality
of terminals therein, said housing including a slot (12) for receiving an elongate
complementary mating electrical component, a plurality of terminal receiving cavities
(22) adjacent said slot adapted for receiving a portion of a terminal therein, and
a plurality of anchoring regions (26) adapted to receive an anchoring portion of a
terminal therein to operatively secure said terminal in said housing;
(b) providing sets of conductive first terminals (28) for selective mounting in the
housing, each of the first terminals having a connection interface section (42), a
tail portion (36) for interconnecting said first terminal to one of said electrical
circuits and a body section distinct from said connection interface section and including
an anchoring portion (34) thereon to secure said first terminal to said housing, said
connection interface section of said first terminals being substantially identical
and including a first resilient contact member (42) extending from a base and having
a first contact portion on said first contact member for contacting a respective electrical
component of said complementary mating electrical component, the terminals of each
set of first terminals having generally planar body sections and with each having
a different surface area than the body sections of the other sets of first terminals
in order to vary the impedance characteristics of each set of first terminals;
(c) providing sets of conductive second terminals (30) for selective mounting in the
housing, each of the second terminals having a connection interface section (44),
a tail portion (36) for interconnecting said second terminal to one of said electrical
circuits and a body section distinct from said connection interface section and including
an anchoring portion (34) to secure said second terminal to said housing, said connection
interface section of said second terminals being substantially identical and including
a second resilient contact member (44) extending from a base and having a second contact
portion on said second contact member for contacting a respective electrical component
of said complementary mating electrical component, said second contact member being
longer than said first contact member, the terminals of each set of second terminals
having generally planar body sections and with each having a different surface area
than the body sections of the other sets of second terminals in order to vary the
impedance characteristics of each set of second terminals;
(d) selecting a terminal from one of said sets of terminals in order to select a terminal
having a desired predetermined impedance substantially similar to the given impedance
of a particular circuit as well as a desired predetermined connection interface section;
and
(e) inserting said selected terminal into said housing;
(f) repeating steps (d) and (e) until terminals are inserted into all of the terminal
receiving cavities of the housing.
13. The method of claim 12 wherein the generally planar body sections of said sets of
first terminals have a generally identical width and the body sections of each set
of first terminals have a different height in the direction of insertion into the
housing and the generally planar body sections of said sets of second terminals have
a generally identical width and the body sections of each set of second terminals
have a different height in the direction of insertion into the housing.
14. The method of claim 12 or 13 wherein said contact arm and said anchoring portion each
extend in a cantilevered manner from a base portion and are spaced apart thereon.
15. The method of claim 14 wherein said anchoring portions are barbs that are press fit
into cavities in said anchoring region.
16. The method of claim 12 wherein the generally planar body sections of at least one
of said sets of terminals have openings (60) therein to reduce the surface area of
body sections.
17. A structure for tuning the impedance of an electrical connector according to claim
1 adapted for interconnecton in a plurality of electrical circuits, each having a
given impedance, comprising:
a set of dielectric electrical connector housings (16) for mounting a plurality of
terminals therein, all of the housings including a substantially identical receptacle
(12) for receiving a complementary mating electrical component, a plurality of terminal
receiving cavities (22) positioned adjacent said receptacle and adapted for receiving
a portion (42, 44) of a terminal therein, and a plurality of anchoring region (26),
each anchoring region being adapted to receive an anchoring portion (34, 34', 34'',
34''') of a terminal therein to operatively secure said terminal in said housing,
at least some of the housings including anchoring regions different from the anchoring
regions of at least some other of said housings for receiving differently configured
anchoring portions of the terminals;
a plurality of sets of conductive terminals (28, 30) for selective mounting in the
set of housings, all of the terminals having a connection interface section (42,44),
a tail portion (36) for interconnecting said terminal to its respective electrical
circuit and an anchoring portion (34, 34', 34'', 34''') separate from said connection
interface section, said connection interface sections being substantially identical
and including a contact arm and a contact portion located thereon, each set of terminals
having generally planar anchoring portions of a different surface area than the anchoring
portions of the other sets of terminals in order to vary the impedance characteristics
of each set of terminals;
whereby the impedance of the electrical connector can be varied without varying the
dimensions of said connection interface sections by selecting a particular set of
said terminals having a desired predetermined impedance substantially similar to said
given impedance and selecting one of said housings having anchoring regions dimensioned
for operatively receiving the anchoring portions of said selected set of terminals
thereat.
18. A structure for tuning the impedance of an electrical connector (10) adapted for interconnection
in a plurality of electrical circuits, each circuit having a given impedance, comprising:
a dielectric electrical connector housing (16) for mounting a plurality of terminals
therein, said housing including a receptacle (12) for receiving a complementary mating
electrical component, a plurality of terminal receiving cavities (22) adjacent said
receptacle adapted for receiving a portion of a terminal therein, and a plurality
of anchoring regions adapted to receive an anchoring portion of a terminal therein
to operatively secure said terminal in said housing;
a plurality of sets of conductive terminals (28, 30) for selective mounting in the
housing, all of the terminals having a connection interface section (42, 44),
a tail portion (36) for interconnecting said terminal to one of said electrical circuits
and a body section distinct from said connection interface section and including an
anchoring portion (34, 34', 34'', 34''') to retain said terminal to said housing,
said connection interface sections being substantially identical including a compliant
contact Portion for contacting a respective electrical component of said complementary
mating electrical component, each set of terminals including general planar body sections
having a different surface area than the body sections of the terminals of the other
sets of terminals in order to vary the impedance characteristics of each set of terminals;
whereby the impedance of the electrical connector can be varied without varying the
dimensions of said connection interface sections by selecting each terminal from a
particular set of said terminals having a desired predetermined impedance substantially
similar to the given impedance of a particular electrical circuit.