EP2858180B1 - Electrical contact element for a plug-in connection with a circuit board - Google Patents

Description

The invention relates to a contact element according to the preamble of patent claim 1.

Such a contact element for use in conjunction with a printed circuit board is already off DE 41 32 996 A1 known. The contact element comprises two spring legs, which are separated by a slot.

Further, suitable for insertion into a circuit board contact elements are made US 6 338 632 B1 . EP 0 138 309 A1 . JP 2000 332370 A . EP 2 639 890 A1 and US 6,231,402 B1 known.

Out EP 0 831 558 A2 For example, a contact element is known which has an elastic deformable plane which makes it suitable for insertion through a through hole in a printed circuit board. In this case, the elastically deformable surface comprises two to each other. parallel spring legs connected by a deformable bridge. This is intended to ensure that the spring legs rest against the inner wall of the bore of the circuit board. The deformable bridge comprises in cross-section a flat portion which extends at right angles to the two opposite spring legs and has an upper and a lower surface. From the opposite ends of the upper surface extend outwardly two inclined portions which adjoin the spring legs.

In electrical connectors there is a requirement to ensure a secure electrical contact even under adverse environmental influences such as temperature fluctuations, mechanical vibrations and the like .. In particular, for use on board a vehicle, the contact reliability must be maintained even under such influences for the entire life.

It is the object of the invention to provide a contact element which has good contact properties and at the same time is inexpensive to manufacture.

According to the invention, this object is achieved in a contact element of the type mentioned, as indicated in claim 1.

The width of the spring leg is dimensioned so that when inserting the contact element into a hole in a circuit board, the spring legs through the wall of the bore, d. H. in the spring area of the spring legs, be compressed and compress. The diameter of the bore is so narrow in at least one region in a spring plane, that the existing of an electrically conductive material contact element can only be resiliently inserted at rest with its spring element, wherein the spring legs inward, d. H. to the gap between them, spring down.

In this compression process takes place at the same time a rotational movement of the spring legs in a direction transverse to the insertion direction cutting plane in the bore. During this rotational movement, the spring legs are guided through the inner wall of the bore and bent in the direction of the center of the bore. In this way, a completely or at least substantially reversible elastic rotation of the spring legs is performed, which leads to a good and wide surface areas of the outer contours of the spring leg comprehensive concerns the spring leg on the inner wall of the bore after completion of the plug-in operation. This has the emergence of broad gas-tight on the inner wall adjacent zones of the spring leg result, over a period of up to 24 hours a Kaltlötverbindung between the spring leg and the region of the inner wall of the bore is formed. Such a Kaltlötverbindung has a good electrical conductivity and a good thermal conductivity. Through the use of the rotational or torsional movement of the spring legs in the bore, a good electrical connection is made with the inner wall of the bore, wherein the Torsional movement of the spring leg at least in its last phase represents a rolling motion on the inner wall of the bore.

During insertion of the contact element, the wall of the bore preferably remains rigid and undamaged. This can create a very advantageous electrical connector between the contact element and the circuit board. With the spring legs, which spring in the gap formed between them, a very precisely metered spring force and a precisely predetermined spring travel are achieved. The resilient mounting within the bore ensures high contact forces and a permanently good contact. Due to the fact that the spring forces continue to act in the mated connection once produced in the bore, the good contact properties are also of long service life even in the case of adverse environmental influences.

A particular advantage of the invention is that the outer contours or individual areas of the outer contours of the spring leg completely or at least over a wide circumference cling tightly to the inner contour of the bore and form a cold soldering with the inner contour, so that the spring legs gas-tight on the inner contour abut and gas-tight contact zones with the wall of the bore form. This prevents the penetration of oxygen and moisture into these areas so that corrosion does not occur. Only the fact that these areas remain corrosion-free, the required electrical conductivity is permanently ensured.

The contact element is preferably made of a copper alloy, in particular of a copper wrought alloy. Especially spring materials are suitable.

Advantageous developments of the invention will become apparent from the dependent claims, the description and the drawings.

It is preferably provided that the spring legs in Toward each other have a trough-shaped depression. Through the trough-shaped depression divided by the gap it is achieved that the spring legs have a high degree of elasticity and, when they are inserted into the bore of the printed circuit board, form a large contact outer area with the bore of the printed circuit board. This assists in the production of a fixed connection to the wall of the bore to the printed circuit board by a cold solder joint.

In a further advantageous embodiment, it is provided that the recess of the spring legs forms a cross-sectionally substantially trapezoidal recess.

Preferably, the fulcrum of this rotational movement is in the region of the gap.

It is also advantageous if the spring legs in cross-section transversely to the insertion direction each have quadrangular contours with rounded corners. In particular, the spring legs in cross-section transversely to the direction of their longitudinal axis forming a first axis on their outer sides in each case quadrangular contours with rounded corners.

It is also advantageous if the spring legs in cross-section in each case to a second and a third axis diagonal direction on the sides facing away from each other, d. H. at the outer edges, each having a trough-shaped recess.

The fact that the spring legs are rounded in each case with advantage at their insertion-side tips in the insertion direction, they can be easily inserted into the bore of a circuit board. It allows a gentle introduction into the circuit board, so that it is spared. As a result, the tracks on the circuit board and surrounding components are little burdened. A buckling of the press-in zone of the circuit board is avoided. The contact element according to the invention has a high elastic deformation proportion, which is higher than that of contact elements according to the prior art.

It is preferably provided that the gap protrudes counter to the insertion direction over the length of the trough in the direction of the contact post. Also By this measure, the elasticity of the spring legs is supported.

Advantageously, the legs in the first direction approximately in the middle of their length each have a wider contour which tapers toward both the contact post and its tips.

Preferably, the trough formed between the legs extends in the first direction, i. H. in the plug-in direction, flatter in the direction of the contact post and also flat in the direction of the tips of the legs, so there rises slightly.

To produce a good and permanent conductivity, a galvanic coating is preferably used. As a result, a particularly low insertion force is ensured in the circuit board and formed by the torsional force of the individual legs an optimal contacting surface for printed circuit board hole. The open tips of the spring legs allow a flat spring characteristic with a particularly gentle and low insertion force when introduced into a bore.

The contacting made possible according to the invention is based on a flexible press-in zone, as formed by the two spring legs. Compared to conventional contact elements, the contact element provided according to the invention has a reduced scattering of the spring force. The shape of the spring legs results in a uniform distribution of the Hertzian stresses and the deformations in the contact zones; in particular, these are much smaller than contact elements according to the prior art. There is only a minimal deformation of the metallic via in the PCB bore, so that the contact element is also suitable for thin circuit boards. Likewise, good self-concentration in the press-in zone is achieved by the selected shape of the spring leg with the trough-shaped recess.

Likewise, the shape of the spring leg also ensures that a large conductor cross-section is present with a large deformation path. This results in a high current carrying capacity with low current heating: The contact element has a compact design that supports the miniaturization.

Fig. 1

eine Draufsicht auf ein Kontaktelement,

Fig. 2

eine Schnittansicht des Kontaktelements gemäß Fig. 1 entlang einer Schnittlinie I - I aus Fig. 1,

Fig. 3

eine Seitenansicht des Kontaktelements,

Fig. 4

eine perspektivische Ansicht der Vorderseite des Kontaktelements,

Fig. 5

eine Ansicht von der vorderen Spitze her,

Fig. 6

eine perspektivische Ansicht der Rückseite des Kontaktelements,

Fig. 7

eine Schnittansicht eines Ausschnitts des Kontaktelements, das in einer Spannvorrichtung eingespannt ist,

Fig. 8a - 8c

perspektivische Ansichten eines Ausschnitts eines mit seinen Federschenkeln in eine Bohrung einer Leiterplatte eingesteckten Kontaktelements von der Rückseite, wobei die Federschenkel in den verschiedenen Steckpositionen die Bohrung der Leiterplatte durchragen, und

Fig. 9a - 9c

zu den perspektivischen Ansichten gemäß Fig. 8a bis 8c zugehörige Schnittansichten, jeweils gemäß einer zugehörigen Schnittlinie VIIIa - VIIIa, Vlllb - Vlllb bzw. Vlllc - Vlllc des Kontaktelements entsprechend den Steckpositionen in der Leiterplatte.

The invention will be explained in more detail with reference to an embodiment. Show it:

Fig. 1

a plan view of a contact element,

Fig. 2

a sectional view of the contact element according to Fig. 1 along a section line I - I out Fig. 1 .

Fig. 3

a side view of the contact element,

Fig. 4

a perspective view of the front of the contact element,

Fig. 5

a view from the front tip,

Fig. 6

a perspective view of the back of the contact element,

Fig. 7

FIG. 3 a sectional view of a section of the contact element which is clamped in a tensioning device, FIG.

Fig. 8a - 8c

perspective views of a section of a plugged with his spring legs in a hole of a printed circuit board contact element from the back, wherein the spring legs in the various plug positions, the bore of the circuit board protrude, and

Fig. 9a - 9c

according to the perspective views Fig. 8a to 8c corresponding sectional views, in each case according to an associated section line VIIIa - VIIIa, VIIIb - VIIIb or VIIIc - VIIIc of the contact element corresponding to the plug positions in the circuit board.

A contact element 1 ( Fig. 1 to 6 ) comprises at its upper end a contact post 2, which in turn carries at its lower end two integrally connected with the contact post 2 and separated by a narrow gap 3 spring legs 4, 5. The gap 3 extends in the direction of a Axis A and preferably has the same width over its entire length; the gap 3 is formed during punching by a shearing process.

The spring legs 4, 5 have on their outer sides in each case convexly curved outer contours 6, 7. In addition, the spring legs have an axisymmetric, the gap 3 cross trough-shaped recess or recess 8, which extends substantially over the entire length of the spring leg 4, 5 or the length of the gap 3, but also a greater or lesser length than the gap 3 can have. At their tips 16 and 17, the spring legs 4, 5 each have a rounding.

The recess 8 forms in cross section ( Fig. 2 ), ie transverse to the direction of the axis A, a substantially trapezoidal recess 9. Laterally of the recess form the spring legs 4, 5 each quadrangular contours 10, 11 and 12, 13, each having rounded corners. In a diagonal direction relative to an axis B and an axis C, a depression 14 is present between the quadrangular contours 10 and 12, and a depression 15 is provided between the contours 11 and 13.

The depression 8 flattens off both in the direction of the contact post 2 and in the direction of the tips 16, 17.

A between jaws 18, 19 ( Fig. 7 ) a tensioning device 20 with its spring legs 4, 5 introduced contact element 1, in particular in the direction indicated by arrows D, E, F, G directions a good contact with the jaws 18, 19th

At the beginning of insertion of the contact element 1 in a bore 21 (FIG. Fig. 8a . Fig. 9a ) in a circuit board whose bore in Fig. 8a - 8c each represented by the dark colored area, the spring legs 4, 5 are first compressed only in the area adjacent to the recess 8 area, so that the gap 3 disappears in this area and only is still preserved in the contiguous to the contours 12, 13 area.

With progressive insertion of the contact element 1 in the bore 21 ( Fig. 8b, 8c ; Fig. 9b, 9c ) widens the gap 3 in the contiguous to the contours 12, 13 region in cross-section wedge-shaped to a gap 3 ' Fig. 8b ) and a gap 3 "( Fig. 8c ), by the contours 12, 13 are guided through the inner wall of the bore 21 and thereby further twisted during insertion.

In this case, the contours 12, 13 are finally a large area on the inner wall of the bore 21 and make a wide contact zone with the bore 21 ago, so that excellent electrical conductivity and thermal conductivity during the transition from the spring legs 4, 5 are generated to the bore 21. At the same time arise large-area gas-tight contact areas .22, 23, in particular, no oxygen can penetrate, whereby corrosion in the contact areas 22, 23 is prevented.

LIST OF REFERENCE NUMBERS

1

contact element

2

Contact post

3

gap

4

spring leg

5

spring leg

6

contour

7

contour

8th

deepening

9

recess

10

contour

11

contour

12

contour

13

contour

14

trough

15

trough

16

top

17

top

18

jaw

19

jaw

20

jig

21

drilling

22

contact area

23

contact area

A

axis

B

axis

C

axis

D

arrow

e

arrow

F

arrow

G

arrow

Claims (7)

1. A contact element (1) for producing a plug-in connection, having a bore (21) that has an inner wall, the contact element (1) being in the form of a contact stud (2) with a spring element attached integrally thereto, which has two parallel spring legs (4, 5), the spring legs (4, 5) being separated from each other in a plug-in direction by a gap (3) that has the same width over the entire length thereof,
   characterised in that the spring legs (4, 5) have a convexly curved outer contour transverse to the plug-in direction and transverse to the gap (3) and can be bent in the bore (21) in a plane transverse to the plug-in direction towards a centre point of the bore (21) and can be deformed by a rotary movement; that the spring legs (4, 5) have an axisymmetric, trough-shaped recess or depression (8), which spans the gap (3) and extends over the entire length of the spring legs (4, 5) or the length of the gap (3); that the trough-shaped recess or the depression (8) has a trapezoidal cross-section; and that the spring legs (4, 5) each form square contours (10, 11, 12, 13), which each have rounded corners, laterally of the recess or depression (8); and that the gap (3) can be widened on the side facing the inner wall of the bore (21).
2. The contact element (1) according to Claim 1,
   characterised in that
   the rotation point of the rotary movement lies in the region of the gap (3).
3. The contact element (1) according to any one of Claims 1 to 2,
   characterised in that
   the spring legs (4, 5) each have, on the sides facing away from each other, a trough-shaped contour (13, 14) in cross-section in a diagonal direction relative to a second (B) and a third axis (C).
4. The contact element (1) according to any one of Claims 1 to 3,
   characterised in that
   the spring legs (4, 5) are each rounded at the tips (16, 17) on the insertion side in the insertion direction.
5. The contact element (1) according to any one of Claims 1 to 4,
   characterised in that
   the gap (3) extends beyond the length of the depression (8) towards the contact stud (2), counter to the insertion direction.
6. The contact element (1) according to any one of Claims 1 to 5,
   characterised in that
   the spring legs (4, 6) each have a wider contour (10, 11) in approximately the centre of their length, in the direction of their longitudinal axis, said contour tapering both towards the contact stud (2) and towards their tips (16, 17).
7. The contact element (1) according to any one of Claims 1 to 6,
   characterised in that
   the depression (8) formed between the spring legs (4, 5) is shallower in the irst direction (A) towards the contact stud (2) and is likewise shallower towards the tips (16, 17) of the spring legs (4, 5).

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