Termination adaptor connector device

Tis termination adaptor connector is provided to receive bulky adaptation and/or simulation elements (4) when there is limited space for the connector and comprises a flexible printed circuit (3) to carry the elements (4) and connect them to the connector (2). The linkage between the connector (2) and the circuit (3) is obtained by means of slit self-stripping connections (6) carried by the same connector, which lock the conductive ends (31) of the circuit (3) in associated slits (60). The entire assembly can then be contained inside a small housing.

FIELD OF THE INVENTION 
The present invention relates to a termination adaptor connector, including 
among other elements a package or housing. A connector of a first type is 
accommodated in the housing and intended to be connected to the end of a 
line over which signals travel of an electronic system having a connector 
of a second type, for adapting the line and/or simulating the connection 
between the line and an external device effectively accommodated in the 
package. Means for supporting and linking adaptation and/or simulation 
elements is connected to the connector of the first type. 
BACKGROUND OF THE INVENTION 
Termination adaptor connectors are currently used to test or adapt an 
electronic system, or to simulate its connection to some other electronic 
system. Examples of such devices may be found in electronic components 
catalogs, more particularly for connectors, published by the 
manufacturers, such as 3M or AMP. To terminate a line, it is presently 
usual to use small-sized connector packages, which may include jumper 
links, electric wires, or adaptation resistors. However, if integration 
with the connector packages of circuits or bulkier elements is desired, 
then rigid printed circuits welded to the connectors are used, and the 
bulky elements are disposed on these circuits. Taking into account the 
relative bulk of the printed circuit and the elements carried by it, this 
necessitates the use of equally bulky connector packages, which may have 
serious disadvantages. There is in fact a strong tendency toward 
miniaturization at present. Thus current electronic systems are 
incorporated in smaller and smaller volumes, and if connector packages 
such as those described above must be used, it becomes impossible in many 
situations because of lack of space to connect the connector packages, or 
at least to connect them without disconnecting the electronic systems to 
be tested. 
Another disadvantage in using connector packages of the type described 
above relates to the difficulty of obtaining effective shielding, because 
to improve the shielding necessitates a further increase in volume. 
OBJECT AND SUMMARY OF THE INVENTION 
The object of the present invention is to effectively overcome the various 
disadvantages discussed above, by a device that is very simple to use, 
offers very good performance, and is of reduced cost. 
To attain this, the termination adaptor connector of the present invention 
is notable in that the support and linking means is a flexible printed 
circuit. Linkage between the connector of the first type and the flexible 
printed circuit is obtained by means of slit self-stripping connections 
carried by the connector, which perforate the insulation, when present, of 
the flexible printed circuit and clasp or capture the conductive ends of 
the flexible printed circuit, which are especially adapted to this end, in 
the slits provided in the self-stripping connections. 
Thus the concept of the invention is to use a flexible printed circuit, 
which by its flexibility makes it possible, in the simplest possible 
manner, to fully utilize the volume inside the connector package while 
effectively supporting even bulky elements. Implementation of this concept 
thus achieves a very significant gain in space. Furthermore, in 
association with the flexible printed circuit, the self-stripping 
connections allow easy, heavyduty use, and the risk of circuit detachment 
is averted, since no other welding is necessary. Finally, effective 
shielding can be attained without difficulty and without increasing the 
volume, because of the use of a flexible printed circuit, taking into 
account its intrinsic properties on the one hand and on the other hand the 
fact that ground planes or lines can be easily integrated into the 
thickness of the insulator when the printed circuit is made. 
In one essential characteristic of the device of the invention, the 
conductive ends of the flexible printed circuit are remarkable in that 
they are not covered with insulation and they have a predetermined width, 
as a function of the width of the slits of the self-stripping connections. 
The width of the conductive ends are slightly greater than the width of 
the slits, so as to assure a forced connection when the connections pierce 
the flexible printed circuit. In this way, each self-stripping connection 
perforates the insulation, if any, on either side of this conductive end, 
while the conductive end is clasped and captured, and can perfectly match 
the shape of the slit. 
It is understood that when the conductive ends protrude freely from any 
support, so that there is no insulation on either side of each of them, 
this self-stripping connection can clasp and capture a conductive end 
directly, without perforation, in such a way that the conductive end 
matches the shape of the slit. The primary importance of using a flexible 
printed circuit the conductive ends of which protrude free of any support 
is the greater ease of adapting the flexible printed circuit to any 
connector; in that case, the flexibility of the conductive end is further 
improved. 
Also characteristically, the ends of the flexible printed circuit are 
remarkable in that they have a thickness that is at least twice as great 
as the thickness of the other conductive portions of the flexible printed 
circuit. 
Furthermore, in an additional characteristic, at least two conductive ends, 
which may or may not be adjacent, can be connected to one another by means 
of conductive ink and metallized holes. The conductive ink may be disposed 
in the thickness of the insulator transversely to the conductive lines, 
while the linkage between conductive lines and conductive ink is obtained 
selectively by means of selective placement of metallized holes. This 
makes it easy to make a linkage between lines and also to further improve 
the shielding when a plurality of ground lines are connected to one 
another at a common point just upstream of the conductive ends. 
According to one embodiment of the invention, the flexible printed circuit 
may also form a loop, the two ends of which are connected to the 
connector. This makes it possible to insert the adaptation and/or 
simulation elements inside the loop, which may also have the effect of 
improving shielding while guaranteeing a major gain in space and great 
ease of insertion into the package. 
To further improve the flexibility and ease of insertion into the package, 
the flexible printed circuit, when it has the shape of a loop, may be 
provided with two transverse cutouts along the same axis, on either side 
of its median portion, each cutout extending over approximately one-third 
the width of the flexible printed circuit and ending inside the circuit in 
a circular recess, in such a manner as to avert any extension of the 
transverse cutouts. 
In order to receive the adaptation and/or simulation elements, the flexible 
printed circuit is provided with conductor sites that are not covered with 
insulation, making it easier to affix the adaptation or simulation 
elements by means of soldering. 
Finally, in a final characteristic of the device according to the 
invention, the conductive ends and the conductor sites not covered with 
insulation of the flexible printed circuit may be protected at the time of 
manufacture by an antioxidant compound, for example, an alloy of lead and 
tin deposited by tinning. 
The following description in conjunction with the accompanying drawings, 
all of them given by example, will enable better comprehension of the 
invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
FIG. 1a proposes an exemplary, non-limiting embodiment of a termination 
adaptor connector, for which the concept of the invention is used and 
implemented. The connector device includes a connector package or housing 
1 comprising an upper portion and a lower portion. Housing 1 may be any 
commercially available package. Use of commercially prefabricated housings 
has the advantage of avoiding special adaptation or machining of this 
part. Accommodated in the package is a connector 2 of a first type (for 
instance, female), intended to be connected to the end of a line of an 
electronic system having a connector (not shown) of a second type (for 
example, male, if the connector of the first type is female), over which 
signals pass, for adapting this line and/or simulating its connection to 
an external device. Also accommodated in the housing 1 and connected to 
the connector 2 is the means 3 for support and linkage of adaptation 
and/or simulation elements 4. The upper and lower parts of the housing 1 
are joined by way of a fasteners 5 (a screw, bolt, clip, etc). 
In accordance with the concept of the invention, the support and linkage 
means 3 is a flexible printed circuit, the linkage of which with the 
connector 2 is obtained by means of self-stripping slit connections 6 
carried by the connector 2 (for example, self-stripping connections made 
by the 3M Corporation). As FIG. 1b shows, a self-stripping connection 6 
perforates the insulation 30 (which is present in this particular example) 
of the flexible printed circuit 3 and clasps the conductive end 31 of the 
flexible printed circuit 3 in the U-shaped slit 60, this end 31 being 
especially adapted for this purpose. To this end, the conductive ends 31 
of the flexible printed circuit 3 are not covered with insulation and have 
a predetermined width, as a function of the width of the slits of the 
self-stripping connections 6 and hence as a function of which such 
connections are selected. Thus the width of the conductive ends must be 
slightly greater than the width of the U-shaped slits, to assure a forced 
connection when the connection comes to clasp the conductive end in its 
slit, which consequently guarantees high-quality contact and also serves 
to capture or imprison the conductive end. 
FIG. 2a shows an exemplary embodiment of a flexible printed circuit, the 
insulation of which may comprise Kapton (trademark registered by E. I. 
DuPont de Nemours and Company), Upilex (trademark registered by Ube 
Industries, Inc.), or any other material having similar characteristics. 
In a known manner, the flexible printed circuit comprises copper links or 
tracks, having a thickness of approximately 100 .mu.m, covered with one or 
more insulating layers on both sides. These copper tracks make it possible 
to connect the adaptation and/or simulation elements (see FIG. 3) to the 
conductive ends 31. 
Thirty-six conductive ends 31a and 31b are shown in the drawing, eighteen 
of them, (31a) on one side of the circuit 3 and eighteen (31b) on its 
other side. Accordingly, such a circuit will be associated with a 
connector that has thirty-six contacts in two rows and hence thirty-six 
self-stripping connections. For the case where the fasteners 5 of the two 
parts of the connector package 1 (FIG. 1a) are screws or bolts, four holes 
32 are made in the flexible printed circuit 3 to enable the passage of 
these fasteners. 
To allow better understanding of the structure of the flexible printed 
circuit 3, an enlargement of this circuit, in the zone outlined by the 
circle C (FIG. 2a) is shown in FIG. 2b, and FIG. 2c shows a section taken 
along the lines AA of the portion shown in FIG. 2b without insulation 30, 
covering ends 31. As shown in FIG. 2c each conductive end of the flexible 
printed circuit 3 may have a thickness at least twice as great, for 
example, being on the order of 250 .mu.m, as the thickness of the other 
conductive parts (the thicknesses of which are approximately 100 .mu.m) of 
the circuit 3. Furthermore, it can be seen that as has been noted above, 
the conductive ends 31 are not covered with insulation. 
FIGS. 2b and 2c also make it possible to see how two conductive ends 31, 
which may or may not be adjacent (in FIG. 2b, they are not adjacent), may 
be connected to one another by means of a linkage of conductive ink 33 and 
metallized holes 34. The conductive ink is disposed in the thickness of 
the insulator (in FIG. 2c, it is disposed between two insulation layers 
35) transversely to the conductor lines 36, while the linkage between 
conductor lines 36 and conductive ink 33 is selectively obtained by means 
of metallized holes 34. A layer of conductive ink may be made, for 
example, by screenprinting using an ink that contains silver. 
In a preferred embodiment of the device according to the invention, the 
flexible printed circuit 3 forms a loop, shown in FIG. 1a, the two ends of 
which, comprising the conductive ends 31a and 31b, are connected to the 
connector 2 (FIG. 1a) by means of connections 6. 
In this preferred embodiment, to further improve the flexibility and ease 
of insertion and arrangement of the flexible printed circuit in the 
package 1 (FIGS. 1a), this circuit 3 is provided with two transverse 
cutouts 37 on either side of its middle portion and extending along the 
same axis xx', each cutout extending over approximately one-third the 
width of the flexible printed circuit 3 and ending inside the circuit in a 
circular recess 370. 
Finally, the flexible printed circuit 3 is provided with conductor sites 38 
that are exposed and not covered with insulation. These sites are provided 
to receive the adaptation and/or simulation elements, such as those 
described in conjunction with FIG. 3. The conductor sites 38 and the 
conductive ends 31a and 31b may furthermore be protected with an 
antioxidant compound 39, for example, an alloy of lead and tin that is 
deposited by tinning at the time the circuit 3 is manufactured, and the 
thickness of which may be approximately 10 .mu.m. 
In FIG. 3, the flexible circuit 3, as described in conjunction with FIGS. 
2a, 2b, 2c, is shown provided with adaptation and simulation elements 4, 
which in this exemplary embodiment may be two integrated circuits such as 
a Texas Instruments ULN 2003D chip, a Motorola MC 1413 D chip, or any 
equivalent, each including a plurality of npn transistors each equipped 
with a base resistor and organized in such a manner as to form Darlington 
assemblies. A termination adaptor connector of this kind makes it possible 
to adapt and simulate a printer, for instance, at the output of a 
computer. 
In conclusion, because of the increase in space gained by the device 
according to the invention, it can advantageously be used when the 
adaptation and/or simulation elements, such as integrated circuits, to be 
inserted into it are very bulky, and when the space for receiving them is 
limited. Its cost is less, because a commercially available package can be 
used without having to be adapted, and it does not require the 
implementation of complex techniques; on the contrary, it is easy to use. 
Moreover, it makes it possible to improve shielding in a simple manner, 
without increasing the volume.