EP0226086A2

EP0226086A2 - Surface mount connector

Info

Publication number: EP0226086A2
Application number: EP86116408A
Authority: EP
Inventors: Manfred Reichardt; Rolf-Dieter Loss
Original assignee: Allied Corp
Current assignee: Allied Corp
Priority date: 1985-12-13
Filing date: 1986-11-26
Publication date: 1987-06-24
Also published as: EP0226086A3; DE3544125A1; JPS62188181A; DE3544125C2

Abstract

A connector adapted to be mounted to a printed circuit board (10) by a surface mount technique, the connector including an insulating body (7) with contact elements (33) arranged therein. The contact elements are connected to termination points (6) on the circuit board by a short conductor section, such as a short length of flat cable (35). One end (49) of the conductors (36) is connected to the contact elements and the other end (46) to the termination points.

Description

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a connector adapted for surface mounting.

Description of the Prior Art

It is already known to surface-mount passive and active components on one side or on both sides of a circuit board (SMD-technique). "SMD" is the abbreviation for "surface-mounted device".
The so-called SMD technique has a number of advantages and consequently the use of this technique continues to increase. Using the SMD technique in connection with the automatic mounting of the components leads to a significant decrease in costs and to a higher preciseness in the mounting operation. For the SMD technique, connectors are available in the form of so-called elongate connectors having male contacts as well as in the form of elongate connectors having female contacts.
For a known SMD connector, a specially designed insulating body is provided and contact legs of special design extend out of the insulating body. The contact legs are adapted to be connected with termination points or dots at the surface of the circuit board. For the known elongate connectors of the male or female type, for instance three rows of contact elements are arranged in a superimposed relationship. Each row of contact elements comprises a plurality of individual contact elements which extend out of the insulating body by means of the contact legs. The contact legs of a set of contact legs arranged in a vertical line have a different length and end in contact feet or tabs which are arranged behind each other in a direction away from the insulating body. The contact feet can be soldered to termination points on the circuit board which are also arranged behind each other, i.e-., away from the connector. This kind of arrangement with termination points being located behind each other requires a relatively large amount of space at the surface of the circuit board. Moreover, as already mentioned, newly designed contact elements having, for instance, termination legs are required, as in an insulating body of special design.
In another known SMD connector, irregular spaces are provided between the contact elements in the connecting region of the connector. This leads to irregular spacings at the circuit board. As a consequence, the circuit board has to be provided with irregularly arranged termination points, or else differently formed contact or termination legs are required which is even more costly.
It would be desirable to provide a connector which overcomes the disadvantages of the prior art.
It would also be desirable to provide an SMD connector which makes use of standard version components, which can be manufactured at low cost and which requires a small amount of space on the circuit board.
It would further be desirable to provide an SMD connector of the multiple-row design such that only a single row of termination points on the circuit board is needed.

SUMMARY OF THE INVENTION

The -present invention provides for a SM_D connector comprising an insulating body, with contact elements arranged in the insulating body and adapted to be connected by termination means to termination points on a circuit board. The termination means is provided in the form of a short conductor piece or section. The conductor section comprises two ends, one end being connected with the contact elements and the other end being adapted to be located adjacent to the termination points for connection therewith.
In accordance with a preferred embodiment of the invention, the conductor piece is a section or piece of a flat cable. Accordingly, the flat cable forms the termination legs of the SMD connector which is created by combining a standard version connector with the flat cable section. Preferably, a short conductor piece is used.
The invention is based on the general concept to provide between the standard version contact elements of a standard connector and the termination points at the surface of the circuit board readily available termination means, i.e. termination means which can be connected on the one hand, to the contact elements of the connector and on the other hand, to the termination points of the circuit board.
Preferably, the termination means are connected and mounted to the connector by means of the so-called insulation displacement technique which , as is generally known, is a special kind of termination technique not requiring the removal of the insulation from the conductor or flat cable. Generally, any termination technique not requiring the removal of the insulation may be used. It is further possible to use any kind of termination technique for connecting the termination means to the connector, preferably a piece of a flat cable, with its end facing towards the connector.
Even though a flat cable is preferred as a termination means, it is also possible to- use a flexible printed circuit, which is known in the art. The use of a flexible printed circuit allows in addition to the spacing defined by the insulation displacement connector the selection of any spacing at the surface of the circuit board. For instance, a fan-out arrangement can be provided at the surface of the circuit board.
The section of flexible circuit is arranged, similar to a section of flat cable, at the connector with such a length that the free end of the section or the end facing towards the circuit board ends such that the conductors of the flexible circuit end adjacent to the termination or solder points at the circuit board. The end of the section of the circuit facing towards the connector is again preferably connected with the connector by means of the insulation displacement technique.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a schematic sectional view of a prior art SMD connector in the form of an elongate connector arranged on a circuit board and having male contact elements.
Figure 2 is a cross-sectional view similar to Figure 1 showing a prior art elongate SMD-connector having female contacting elements.
Figure 3 is an isometric partially cut rear view of a _SMD-connector of the trapezoidal type employing a connector as defined in German standard DIN 41652.
Figure 4 is partial isometric rear view of a second embodiment of an SMD-connector based upon a connector known from German standard DIN 41612.
Figure 5 is a schematic side view of the SMD-connector of the type shown in Figure 4.
Figure 6 is an enlarged view of a detail referred to by reference numeral 50 in Figure 5.
Figure 7 is a view similar to Figure 6 showing a modification of the design shown in Figure 6.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figure 1 illustrates a connector 1 for surface mounting, i.e., an SMD-connector. Connector 1 is shown as an elongated connector having male contacts and comprising three rows of contact elements 8 which are arranged in a superimposed relationship. The male contact elements are provided in the form of so-called contact pins or contact knives. Obviously a plurality of rows of contact elements 8 as shown are arranged extending into the plane defined by the drawing sheet and also extend out of said plane.
Contact elements 8 are located in an insulating body 7 which is placed on a surface 11 of a printed circuit board 10 and is fixedly mounted thereto.
Surface 11 of the circuit board 10 is provided with termination points or termination dots 6 adapted to provide a connection to the SMD components as well as to connector 1. One of the SMD components is referred to by reference numeral 14.
SMD termination means 3 is provided in the form of termination legs 4 so as to provide a connection to contact elements 8. Each of contact elements 8 comprises a contact end 12 and a termination end 13. Each one termination leg 4 is associated with each one termination end 13 of each one contact element 8. Each termination legs 4 connects the respective termination end to the corresponding termination point 6. Each termination leg 4 comprises a termination foot 5 for contacting the appropriate termination point. Typically, termination feet 5 of the connector 1 as well as the termination feet of the SMD component 14 are soldered to termination points at a circuit board for providing the required connection, for instance by the so-called vapr phase soldering method or the so-called reflow soldering method.
Figure 2 shows a connector similar to the one shown in Figure 1. However, the SMD-connector 9 of Figure 2 is designed in the form of an elongate SMD-connector, i.e. in an insulating body 18 female contact elements 17 are arranged instead of the male contact elements shown in Figure 1. Again, termination means 3 connects female contact elements 17 to the termination points at surface 11 of circuit board 10.
Figure 3 illustrates a first embodiment of an SMD-connector 30 of this invention. SMD-connector 30 is in the form of a standard version connector 31, for instance a connector according to German standard DIN 41652, and termination means 3 which makes it possible that standard version connector 31 can be used as a SMD-connector 30.
In accordance with this invention termination means 3 is provided in the form of a piece or section of a conductor means. Preferably, the connector means is provided in the form of a section or piece of flat cable 35. Flat cable section 35 preferably has'a short length and comprises an end facing towards the circuit board, i.e. a circuit board end 46 and an end which faces towards the connector, i.e. a connector end 49.
Flat cable section 35 is termination with its connector end 49 at the termination ends of contact elements 33 of the connector. In the embodiment shown this termination is carried out by the preferred insulation displacement contact ("IDC") technique. For that reason connector 31 is designed for the insulation displacement technique. Connector 31 comprises, besides an insulating body 32 supporting contact elements 33, a support member 37 which forms a support surface 39 for flat cable 35. A holding bracket 38 having an upper longitudinal edge 40 and a lower longitudinal edge 41 completes the IDC connector 31.
Figure 3 illustrates that standard connector 31 is mounted to surface 11 of the circuir board 10 by means of mounting angles 43. As was discussed earlier, surface 11 is provided , in a known manner, with termination points 6, which are typically in the form of conductive pads, and which have to be connected to contact elements 33 of the connector 31. This is done by means of flat cable section 35. Flat cable section 35 is guided around lower longitudinal edge 41 forming approximately a right angle. The insulating sheath 42 is removed from the free or circuit board end 46 of flat cable section 35 in the area of the termination points 6, so that the conductors or wires 36 of the flat cable are accessible for contacting termination points 6. It is preferred that flat cable section 35 extends with its insulation sheath beyond longitudinal edge 41. Preferably, insulation sheath 42 of flat cable section 35 is removed only in the area outside of connector 31.
It will be appreciated that the use of the short flat cable section changes connector 31, which could not be used as a SMD-connector, into a useful SMD connector 30.
Typically, SMD-connectors are subjected to high temperatures, in particular during soldering operations, so that only such connectors 31 and only such flat cable sections 35 may be used, which can sustain such temperatures. These requirements are fulfilled for many of the materials from which connectors and cables are made, so that changes in standard designs are not required.
Figure 4 discloses a second embodiment of a SMD-connector 70. SMD-connector 70 comprises in substance a customary known connector 72, for instance of the type in accordance with German standard DIN 41612, as well as termination means 3 in the form of a short flat cable section 35. Connector 72 is fixedly mounted to the upper surface 11 of circuit board 10 by means of mounting angle 43. A mounting bracket 73 maintains flat cable section 35 in accordance with the insulation displacement technique in connection with the contact elements (not shown) of connector 72. Circuit board end 46 of flat cable 35 ends parallel with respect to the upper surface 11, so that conductors 36 can be soldered to the termination points, which are not shown in Figure 4.
Figures 5 and 6 illustrate in some detail for one conductor 36, how the conductors 36 are soldered to termination points or pads 6 at upper surface 11 of circuit board 10. As can be seen, conductor 36 which is free from the insulating sheath is preferably arch-shaped, so that the convex apex of the arch will touch the corresponding termination point. The wedge-shaped spaces which occur at both sides of that termination point serve as a receiving means for the solder 48.
In Figure 5 a connector 44 adapted for cooperation with connector 31 is also shown.
Figure 7 refers to a preferred modification according to which the insulating sheath or material 47 is only partially removed. Insulating material 47 which was removed from the blank conductor 36 is retained at the outermost end of the otherwise stripped conductor 36. By leaving the partially removed insulation at the ends of the conductors of the flat cable the positioning of conductors 36 according to the spacing of the termination points will be simplified. Besides increasing the preciseness of the positioning operation, the only partially removed insulation will provide a protection of the ends of conductors 36 with respect to bending.
Preferably, the flat cable section extends (see Figures 5 to 7) out of the connector in such a manner that conductors 36 resiliently abut at the termination points so as to provide for a good contacting relationship.
It should be noted that it is possible to use instead of flat cable section 35 a section of a so-called flexible circuit. The flexible circuit comprises in substance a plurality of conductors and it is used similarly as flat cable section 35.
The embodiments shown make use of connectors adapted for the IDC technique, so as to connect the termination means with a standard version of a connector. It is also possible to use standard versions of connectors which use a different kind of termination technique requiring the removal of the insulation. Generally, a connector designed for any kind of termination technique can be used.
It can be seen that the present invention provides an SMD connector which can utilize standard components of a connector. The connector can be manufactured at low cost and requires only a small amount of space on the circuit board. Finally, the invention provides for a single row of termination points on a circuit board for a connector having multiple rows of contacts.

Claims

1. A connector adapted to be surface mounted to a printed circuit board, said connector comprising an insulating body, contact elements arranged in said insulating body, and termination means adapted for connecting said contact elements with termination points (6) arranged on said circuit board (10), characterized in that said termination means is' formed by a short conductor section (35), said conductor section comprising two ends, a first end (49) by means of which said conductor section is connected to said contact elements, and a second end (46) which is adapted to be located adjacent to said termination points (6) for connection therewith.

2. The connector of claim 1, characterized in that said conductor section is a flat cable section (35).

3. The connector of claim 1, characterized in that said connector section is a flexible circuit section.

4. The connector is one or more of the preceding claims, characterized in that said connector is of the insulation displacement type.

5. The connector of one or more of the preceding claims, characterized in that said second end (46) of said conductor section is free of insulation in the area of contact with said termination points (6).

6. The connector of one or more of the preceding claims, characterized in that insulation material (47) is retained at the outermost end of said conductor (36).

7. The connector of one or more of the preceding claims, characterized in that a standard connector for insulation displacement termination- of a flat cable is used together with a flat cable section, and that the insulation is removed from said second end of said flat cable to cooperate with said termination points which are arranged in a single row on the circuit board.

8. The connector of one or more of the preceding claims, characterized in that said contact elements (33) are arranged in multiple rows in said insulating body (7) and said second ends (46) of said conductors (36) are arranged adjacent to each other so as to be able to be connected with termination points (6) which are arranged in a single row on said circuit board (10).

9. The connector of claim 2, characterized in that said connector comprises a holding bracket (38) adjacent to said flat cable section (35) for holding said flat cable section in said connector, said flat cable section being guided beneath said holding bracket at approximately a right angle so as to be parallel to the upper surface (11) of said circuit board (10).

10. The connector of claim 9, characterized in that the insulation is removed from said second ends (46) of said conductor in the area of contact with said termination points (6), but that the insulation extends under said holding bracket.