WO2013004576A1

WO2013004576A1 - Electrical contact element

Info

Publication number: WO2013004576A1
Application number: PCT/EP2012/062506
Authority: WO
Inventors: Rudi Blumenschein; Helge Schmidt
Original assignee: Tyco Electronics Amp Gmbh
Priority date: 2011-07-01
Filing date: 2012-06-27
Publication date: 2013-01-10
Also published as: DE102011078545A1

Abstract

An electrical contact element has a contact body having a receiving region which is orientated in an insertion direction and a contact spring which protrudes into the receiving region and which is in abutment with the contact body in an abutment region. The contact body has, in the abutment region, a notch which is orientated parallel with the insertion direction and which is directed towards the contact spring.

Description

ELECTRICAL CONTACT ELEMENT

The invention relates to an electrical contact element according to the pre-characterising clause of patent claim 1 and a method for producing an electrical contact element according to patent claim 8.

Electrical contact elements with which printed strip conductors are intended to be provided are known from the prior art. Such contact elements are soldered into contact openings or holes of the printed strip conductor and have a receiving region for receiving a contact pin of an electrical component. In this receiving region, there is arranged at least one contact spring of the contact element which fixes a contact pin inserted into the receiving region in the receiving region. In this instance, the contact spring directly abuts a wall of a contact body of the contact element. The contact element has a tin-coated surface.

It has been found that, when such a conventional contact element is soldered into a contact opening of a printed circuit board, unintentional melting of the tin-coated surfaces of the contact body and contact spring of the contact element may occur. The mechanical properties of the contact spring thereby change, which results in a contact configuration force which differs from the desired value. Furthermore, owing to a capillary effect, solder may rise while the contact element is being soldered in and thereby adhesion or soldering of the contact spring and contact body and clogging of the receiving region may occur.

There is known from DE 101 31 225 Al an electronic component having contact pins which, in order to prevent the formation of undesired contact bridges, have soldering stop portions in the form of embossed transverse grooves.

An object of the present invention is to provide a contact element in which the risk of unintentional soldering of the contact spring and contact body is reduced. This object is achieved by an electrical contact element having the characterising features of patent claim 1. An object of the present invention is further to set out a method for producing such an improved electrical contact element. This object is achieved by a method having the features of claim 8. Preferred developments are set out in the dependent claims. An electrical contact element according to the invention comprises a contact body which has a receiving region which is orientated in an insertion direction. The contact element further comprises a contact spring which protrudes into the receiving region, the contact spring being in abutment with the contact body in an abutment region. Furthermore, the contact body has in the abutment region a notch which is orientated parallel with the insertion direction and which is directed towards the contact spring.

Advantageously, the contact face between the contact body and the contact spring is reduced by the notch in the abutment region. The surface of the region in which unintentional soldering may occur is also thereby reduced. This results in a reduced risk of unintentional soldering. Furthermore, unintentional soldering which nonetheless occurs may be separated again in a simpler manner where applicable. Another advantage of the contact element according to the invention is that, owing to the notch which is arranged in the abutment region and an air cushion which is arranged in the notch, a capillary effect is reduced. The danger of unintentional soldering of the contact element and contact spring in the abutment region is also thereby reduced.

The contact spring is preferably constructed in an integral manner with the contact body. Advantageously, a contact element which is constructed in this manner can be produced in a simple and cost-effective manner.

It is advantageous for the notch to be produced by means of embossing. Advantageously, embossing is a cost-effective production method which is suitable for mass production.

In a preferred embodiment of the contact element, the contact body has in the abutment region a plurality of parallel notches. Advantageously, the contact face between the contact body and contact spring in the abutment region is thereby further reduced.

In a development, the contact element has another contact spring. Advantageously, a contact element which is provided with two contact springs can retain a contact pin in the receiving region in a particularly effective manner. It is advantageous for a surface of the contact element to be tin-coated. Advantageously, the contact element can then be soldered to a printed circuit board in a particularly simple manner.

The contact element is preferably produced from a punched bent component. Advantageously, the contact element can then be produced in a cost-effective manner and in large batch quantities.

A method according to the invention for producing an electrical contact element has steps for producing a punched bent component, for embossing a notch in an abutment region of the punched bent component, for tin-coating a surface of the punched bent component and for folding the punched bent component in order to obtain a contact element having a contact body and a contact spring, the contact spring being in abutment with the contact body in the abutment region. Advantageously, in an electrical contact element which is produced in accordance with this method, there is a reduced risk of unintentional soldering of the contact body and contact spring in the abutment region between the contact body and contact spring.

The invention is explained in greater detail below with reference to Figures, in which:

Figure 1 is a sectioned illustration of an electrical contact element, and

Figure 2 is a view of a semi-finished product for producing an electrical contact element.

Figure 1 is a sectioned view of a contact element 100. The contact element 100 comprises an electrically conductive material, preferably of metal. The contact element 100 is provided to be arranged and soldered in a contact opening or hole of a printed circuit board. The contact element 100 serves to receive a contact pin of an electrical component in order to produce an electrically conductive connection between the contact element of the electrical component and a strip conductor of the printed circuit board.

The contact element 100 has a contact body 400 which is substantially in the form of an elongate hollow cylinder with a rectangular cross-section. In a region which is arranged at a longitudinal end of the contact body 400, the contact element 100 has an insertion portion 140 which is orientated parallel with the longitudinal extent direction of the contact body 400 and which tapers in a conical manner at the end thereof remote from the contact body 400. The insertion portion 140 is provided to be inserted into a contact opening or contact hole of a printed circuit board and to be soldered at that location. The longitudinal extent direction of the contact element 100 is then orientated perpendicularly relative to the plane of the printed circuit board. The conically tapering configuration of the insertion portion 140 facilitates the introduction of the insertion portion 140 into the contact opening or hole of the printed circuit board.

The contact element 100 further has a receiving region 110. The receiving region 110 extends from an opening at a longitudinal end of the contact body 400 facing the insertion portion 140 in an insertion direction 120 which is parallel with the longitudinal extent direction of the contact element 100 into the region of the contact element 100 surrounded by the cylindrical contact body 400. The receiving region 110 is provided to receive a contact pin which is inserted into the receiving region 110 in the insertion direction 120. This may, for example, be a contact pin of an electrical component, for example, a contact pin of an integrated circuit.

A first contact spring 200 and a second contact spring 300 are arranged in the receiving region 110 of the contact element 100. The contact springs 200, 300 are arranged in the receiving region 110 in such a manner that a contact pin which is inserted into the receiving region 110 extends between the first contact spring 200 and the second contact spring 300. The first contact spring 200 and the second contact spring 300 extend substantially parallel with the walls of the contact body 400, but each have a plurality of bends at which the directions of extent of the contact springs 200, 300 change slightly in each case. The contact springs 200, 300 delimit a hole size 130 of the receiving region 110 which is measured perpendicularly relative to the insertion direction 120. Furthermore, the contact springs 200, 300 can be resiliently deformed in such a manner that a contact pin which is inserted into the receiving region 110 and whose diameter substantially corresponds to the size of the hole 130 is retained in the receiving region 110 of the contact element 100 in a resilient manner. In this manner, there is an electrically conductive connection between the contact pin arranged in the receiving region 110 and the contact springs 200, 300 of the contact element 100. The contact body 400 of the contact element 100 and the contact springs 200, 300 of the contact element 100 are preferably constructed in an integral manner. The first contact spring 200 is connected in a first connection region 220 to the contact body 400. The second contact spring 300 is connected in a second connection region 320 to the contact body 400. The first connection region 220 and the second connection region 320 are arranged in the radial vicinity of the opening of the receiving region 110 at the longitudinal end of the contact element 100. Owing to the integral configuration of the contact element 100, an electrically conductive connection between a contact pin which is inserted into the receiving region 110 and the contact springs 200, 300 also brings about an electrically conductive connection between the contact pin and the contact body 400 of the contact element 100 and an electrically conductive connection between the contact pin and the insertion portion 140 of the contact element 100. In this manner, the contact element 100 provides an electrically conductive connection between the contact pin which is inserted into the receiving region 110 of the contact element 100 and a contact opening or hole of a printed circuit board in which the insertion portion 140 of the contact element 100 is inserted.

Inside the contact body 400, the first contact spring 200 touches the contact body 400 in a first abutment region 210. In other words, the first contact spring 200 is supported in the first abutment region 210 on the contact body 400. Furthermore, the second contact spring 300 touches the contact body 400 inside the contact body 400 in a second abutment region 310. The second contact spring 300 is supported in the second abutment region 310 on the contact body 400.

The entire surface of the contact element 100 is preferably tin-coated. Consequently, the surfaces of the contact body 400, the insertion portion 140 and the contact springs 200, 300 are tin-coated. If the contact element 100 is heated, there could occur melting of the tin- coated surfaces of the contact springs 200, 300 and the contact body 400 in the abutment regions 210, 310 and subsequent unintentional soldering of the contact springs 200, 300 to the contact body 400 in the abutment regions 210, 310. Such soldering of the contact springs 200, 300 to the contact body 400 in the abutment regions 210, 310 is undesirable and disadvantageous since the mechanical resilient properties of the resilient elements 200, 300 are thereby changed. This would thereby also result in a change in the force which is required in order to insert a contact pin into the receiving region 110 of the contact element 100.

If the contact element 100 with the insertion portion 140 is inserted into a contact opening or hole of a printed circuit board, and if the insertion portion 140 is soldered to the contact opening or hole of the printed circuit board, it may further result in solder rising in the cylindrical contact body 400 of the contact element 100 owing to the capillary effect. This may also lead to unintentional soldering of the contact springs 200, 300 to the contact body 400 in the abutment regions 210, 310. Furthermore, solder which has risen into the contact body 400 owing to the capillary effect may harden at that location and block the receiving region 110 of the contact element 100. A contact pin is thereby prevented from being inserted into the receiving region 110 of the contact element 100.

In order to prevent unintentional soldering of the contact springs 200, 300 to the contact body 400 in the abutment regions 210, 310 and to prevent solder from rising in the contact body 400 owing to a capillary effect, the contact body 400 has at the surface facing towards the first contact spring 200, in the first abutment region 210, a plurality of first notches 420 which are orientated parallel with the insertion direction 120. Nine parallel first notches 420 may, for example, be provided. Furthermore, a surface of the contact body 400 facing the second contact spring 300 in the second abutment region 310 has a plurality of second notches 430 which are orientated parallel with the insertion direction 120. Nine parallel second notches 430 may, for example, be provided. Alternatively, instead of a plurality of notches 420, 430, only one notch 420, 430 may also be provided in each case. The notches 420, 430 are preferably produced by means of embossing.

The notches 420, 430 reduce the support face between the contact springs 200, 300 and the contact body 400 in the abutment regions 210, 310. The risk of unintentional soldering is thereby reduced. Furthermore, unintentional solder connections which are nonetheless produced between the contact springs 200, 300 and the contact body 400 can be more readily broken up. Furthermore, air cushions which are arranged in the notches 420, 430 prevent solder from rising owing to the capillary effect from the insertion portion 140 into the receiving region 110 of the contact body 400.

Figure 2 is a plan view of a semi-finished product for producing the contact element 100 illustrated in Figure 1. The semi-finished product is a punched bent component 500 which has been punched or cut from a metal sheet.

The punched bent component 500 has a first portion 1140 and a second portion 1145 from which the insertion portion 140 of the contact element 100 is jointly formed. The punched bent component 500 further has a third portion 1200 from which the first contact spring 200 is formed. The punched bent component 500 further has a fourth portion 1300 from which the second contact spring 300 is formed. Furthermore, the punched bent component 500 has a fifth portion 1400 from which the contact body 400 of the contact element 100 is formed. The fifth portion 1400 is connected to the third portion 1200 by means of the first connection region 220. Furthermore, the fifth portion 1400 is connected to the fourth portion 1300 by means of the second connection region 320.

The fifth portion 1400 of the punched bent component 500 has the abutment regions 210, 310 in which the contact springs 200, 300 which are formed from the third portion 1200 and the fourth portion 1300 later move into abutment. In the abutment regions 210, 310, the fifth portion 1400 has a plurality of first notches 420 and a plurality of second notches 430. The notches 420, 430 are preferably embossed in the punched bent component 500.

The surface of the punched bent component 500 is tin-coated. The contact element 100 of Figure 1 is produced from the punched bent component 500 of Figure 2 by means of folding or bending. To this end, the punched bent component 500 has a first folding line 510, a second folding line 520, a third folding line 530 and a fourth folding line 540. At each of these folding lines 510, 520, 530, 540, the punched bent component 500 is bent through approximately 90°.

Furthermore, the third portion 1200 of the punched bent component 500 is brought into an undulating form and in the first connection region 220 is bent through approximately 180° in order to form the first contact spring 200 which is then in abutment in the first abutment region 210. Furthermore, the fourth portion 1300 is brought into an undulating form and bent in the second connection region 320 through approximately 180° in order to form the second contact spring 300 which is then in abutment in the second abutment region 310. Subsequently, the contact body 400 of the contact element 100 that is produced from the fifth portion 1400 is closed by means of a pin 550 and a groove 560.

A method for producing a contact element 100 consequently comprises method steps for producing the punched bent component 500, for embossing the notches 420, 430 in the abutment regions 210, 310 of the punched bent component 500, for tin-coating a surface of the punched bent component 500 and for folding the punched bent component 500 in order to obtain the contact element 100 with the contact body 400 and the contact springs 200, 300, the contact springs 200, 300 being in abutment with the contact body 400 in the abutment regions 210, 310. The sequence of the mentioned method steps may vary.

Claims

1. Electrical contact element (100)

having a contact body (400) which has a receiving region (110) which is orientated in an insertion direction (120),

the contact element (100) having a contact spring (200, 300) which protrudes into the receiving region (110),

the contact spring (200) being in abutment with the contact body (400) in an abutment region (210),

characterised in that

the contact body (400) has, in the abutment region (210), a notch (420) which is orientated parallel with the insertion direction (120) and which is directed towards the contact spring (200).

2. Contact element (100) according to claim 1,

the contact spring (200) being constructed integrally with the contact body (400).

3. Contact element (100) according to either of the preceding claims,

the notch (420) being produced by means of embossing.

4. Contact element (100) according to any one of the preceding claims,

the contact body (400) having a plurality of parallel notches (420) in the abutment region (210).

5. Contact element (100) according to any one of the preceding claims,

the contact element (100) having an additional contact spring (300).

6. Contact element (100) according to any one of the preceding claims,

a surface of the contact element (100) being tin-coated.

7. Contact element (100) according to any one of the preceding claims,

the contact element (100) being produced from a punched bent component (500).

8. Method for producing an electrical contact element (100) which has the following steps:

- producing a punched bent component (500);

- embossing a notch (420, 430) in an abutment region (210) of the punched bent component (500);

- tin-coating a surface of the punched bent component (500);

- folding the punched bent component (500) in order to obtain a contact element (100) having a contact body (400) and a contact spring (200), the contact spring (200) being in abutment with the contact body (400) in the abutment region (210).