EP1997187A1

EP1997187A1 - Contact pin and method for its production

Info

Publication number: EP1997187A1
Application number: EP07723163A
Authority: EP
Inventors: Wiestaw Kramski
Original assignee: Kramski GmbH
Current assignee: Kramski GmbH
Priority date: 2006-03-12
Filing date: 2007-03-10
Publication date: 2008-12-03
Also published as: CN101401264A; CN101401264B; WO2007104500A1; DE102006011657A1; US7344389B2; US20070212907A1; JP2009529686A

Abstract

A contact pin (10) for being pressed into a plated-through hole of a printed circuit board is produced by deformation. Its press-in section (13) has two contact limbs (15), which are spaced apart from one another by an elongated opening (14), are curved in their central region towards the outside and come to bear against the wall of the hole when pressed into the hole of the printed circuit board, with plastic deformation. An insertion section (16) is formed for insertion into the hole (11) by at least two elongated sections (17) of the contact pin (10) which bear against one another during the insertion. The sections (17) adjoin the elongated opening (14), which is open towards the outside, in the manner of fork prongs after the deformation process and before the insertion into the hole (11). As a result of the fact that at least one integral formation (18), which protrudes into the opening, is provided for forming supporting regions for controlling the elastic-plastic response in the hole diameter at the edge of the elongate opening (14), a contact pin, and a method for its production, is provided which can be produced by means of stamping in accordance with standards with optimum withdrawal forces.

Description

Contact pin and method for its manufacture

description

Related to related applications

The present application claims the priority of German Patent Application 10 2006 011 657.7, filed on March 12, 2006, the disclosure of which is hereby expressly made the subject of the present application.

Field of the invention

The invention relates to a contact pin with a contact and a connection area for pressing into a plated-through hole of a printed circuit board according to the preamble of claim 1 and a method for its production according to the preamble of claim 13.

State of the art

Such contact pins are particularly intended to produce by soldering in metallized holes of electrical circuit boards a solderless, electrically conductive connection to at least one conductor of the circuit board. For perfect contacting of the perforation whose manufacturing tolerances must be compensated by appropriate configurations of the press-in portion of the contact pin, so that a preferably gas-tight connection between the perforation and press-fit is guaranteed. For this purpose, the press-in sections of such contact pins are plastically deformable against corresponding force on the one hand, and on the other hand corresponding demands are made with respect to the pull-out forces on the elastic properties after insertion. These properties are achieved, for example, by punching into the contact pin in the press-in section a slot-like elongated hole, so that two contact legs, which are resiliently movable toward one another, are formed. The connection produced by the contact pin or press-in pin must meet various electrical and mechanical requirements and also has to pass extensive tests. The main features of this compound are: - low contact resistance

- no contact corrosion,

- optimal insertion forces,

- optimal pull-out forces,

- temperature resistance, - vibration resistance,

- If possible, no chip formation during pressing

This property profile is achieved by means of contact pins or press-in pins which have an elastic-plastic area in order to bridge the hole tolerances of the boards on the one side and to ensure the desired insertion and removal forces and the contacting on the other side.

From the preamble of claim 1 underlying DE 10 2004 028 202 A1 discloses a press-in contact is known, which is made of a material to form two spaced-apart, initially as required open sections without cutting, later forming the Einführpin each other in Appendix. The cross-sectional shape of the sections is selected so that they clamp selectively with the walls in the hole of a circuit board, which can lead to tin abrasion and stress on the hole edge. The goal there is a non-cutting produced pressing-in contact, wherein the hole cross-section is almost completely filled by a cross-sectional shape approximating the square. Especially with decreasing sheet thickness (smaller than, for example, 0.8 mm) and smaller hole diameter, lower clamping forces are always generated, so that a permanently secure electrical connection is at risk.

US Pat. No. 6,135,813 A shows an insertion pin which has at its front end two nearly opposite projections which come to lie outside the hole in the state introduced into the printed circuit board. From the pin diameter to the outside projecting projections anchor the pin after passing the pin through the hole of the circuit board, while the inwardly projecting projections do not distort each other and in no way change, but if necessary, soldered together in position and secured with it. So they do not affect the behavior in the hole of the circuit board.

From EP 0 655 798 A2 a contact pin is known, which is punched out of a material, and before formation of the contact element has two spaced-apart portions, which later form the Einführpin. In each of the sections a needle-tube-shaped opening is provided. By bending over, the two sections are placed against each other, wherein by corresponding pre-deformation, the two ends of these sections are placed against each other, so that the Einführpin results, which can then be inserted into a plated-through hole of a printed circuit board. However, the free ends are not interconnected.

Another contact pin is disclosed in US-A 3,400,358, in which a pair of outwardly curved cables are soldered together at their ends to form the insertion pin. The facing surfaces of the cables can be flattened at their ends to facilitate soldering. This manufacturing process is complex and not lot-free.

The production of such contact pins is usually carried out by punching the contact pins with the introduction of central longitudinal slots, which allow the elastic behavior, as is known for example from DE 195 08 133 C2 or DE 198 31 672 B4. In this case, with ever smaller dimensions of the contact pins and increasing tolerances of the perforation of the printed circuit boards, an ever lower tolerance of the connection is required. The central slot is optimized based on the requirements of the insertion and removal forces, whereby the production technology comes to its limits when punching, for example as a result of stamp stability. In the current stamping technology, the inner shape of the slot is limited by punching and cutting forces to a certain size, since they can not be produced otherwise. As a result, a compromise is achieved in the area of the pin or lead-in area which has the first contact with the printed circuit board during assembly to a barely or non-elastic zone leads, because, for example, by punching a tapered edge of the opening in this area can hardly be made hergesteiit. This can cause shavings of the surface, which can generate shorts as chips. Since the diameter tolerance of the perforations of the printed circuit boards, which is covered by a Einpressabschnitt, rarely meets the standard, corresponding pins are used only with narrow tolerances of the PCB hole diameter.

Contact pins with embossed zones are also e.g. from JP 03 017971 A or US 4,923,414 A known, in which case usually the press-in portion is formed so that it can deform plastically during pressing. These pins usually do not cover the range of the standard accordingly. In addition, the manufacturing is very sensitive to tolerances and the risk of shaving is relatively high.

In order to improve the properties and in particular the pull-out forces, several attempts have also been made to provide projections in the region of the longitudinal slot between the contact limbs of the press-in section which, for example, are pressed into the perforation of the printed circuit board during pressing. overlap (see DE 37 84 911 12) or to provide this area with projections which come into contact with one another during the deformation (compare EP 0 387 317 B1). The limits of this embodiment are in turn the limits of stamping technology, since pins are barely produced by punching in a further miniaturization.

Object of the invention

Based on this prior art, the present invention seeks to provide a contact pin and a method for its production, which is produced by stamping standard with optimal extraction forces.

This object is achieved by a contact pin having the features of claim 1 and by a method having the features of claim 13. The contact pin has an open shape in which after the punching operation, the later slot forming iängiiche opening is open to the outside and lies between the sections that later form the insertion of the contact pin. With the initially open fork-like shape of these sections, which then abut each other when inserted into the hole, the limitations of punching technology can be circumvented. At the same time, any basic shape of a contact pin can be easily made larger or smaller, ie the press-in and Auspresskräfte can be better defined and are eg softer and harder in the transitions, which is not possible in today's punching technology with a closed Needle-Eye. Within the elongated opening, any geometric formations are formed, thereby forming, for example, support areas. These support areas can control the elastic-plastic behavior over the different hole diameters. For this purpose, the projections can preferably come to rest in the hole itself. But they can also lead to a kind of tilting movement, which makes the area pushed through the hole wider than the pressing area, which leads to increased extrusion forces. As a result, even with decreasing sheet thickness and smaller hole diameter still good clamping forces can be generated. Tests have shown that even with small hole diameters of 1.0 mm and sheet thicknesses of 0.6 mm, a secure connection can still be achieved.

The moldings or support areas produced by preferably chip-producing production or forming are no longer made contiguous with increasing miniaturization of the contact pins. Instead, an open opening is first punched out in order to release the moldings there. The press-in area of the contact pin is analogously produced as an open fork, which eliminates the manufacturing restrictions. Preferably, at the end of the stamping process or better forming process, the contact pin can be closed, for example mechanically, by welding, riveting, laser welding or the like, whereby the elongate opening or the slot then preferably forms in the middle. As a result, for example, the slot can be made tapering in the front region in the insertion direction, so that there is less material there is that during insertion of the press-in portion of an elastic deformation in the way.

Further advantages emerge from the subclaims and the following description.

Brief description of the figures

The invention will be explained in more detail below with reference to the attached drawings. Show it:

1, 2 is a view of a contact pin in the punched, open state and in a state in which the ends of the contact pin are connected to each other, Fig. 3 is an enlarged view of the front portion of the contact pin of FIG. 2,

4 is an enlarged view of the contact pin of FIG. 1,

5 is a section along line 5-5 of Fig. 3,

6 shows a contact pin with notched outer edges in a further exemplary embodiment,

7 shows the contact pin according to FIGS. 1 to 5 in a state introduced in the hole of a printed circuit board, FIG.

8 is a section along line 8-8 of Fig. 7,

9 shows a view analogous to FIG. 8 with a variant of the product contour, FIG. 10 shows a view of a contact pin in a further embodiment in which the projections come to lie in the hole of a printed circuit board,

Fig. 11, 12 views of the contact pin when mounted in printed circuit board holes of different diameters.

Detailed description of preferred embodiments

The invention will now be described by way of example with reference to the accompanying drawings. However, the exemplary embodiments are only Examples that are not intended to limit the inventive concept to a particular arrangement. Before describing the invention in detail, it should be understood that it is not limited to the particular components of the apparatus or the illustrated approach, as these components and methods may vary. The terms used herein are intended only to describe particular embodiments and are not intended to be limiting. When the singular or indefinite articles are used in the specification and claims, these also refer to the majority of these elements unless the context clearly makes otherwise clear. The same applies in the opposite direction.

The figures show a contact pin 10 of a formed material for pressing into a plated-through hole 11 on a printed circuit board 12, which is shown in FIG. If in the following a forming or forming process is mentioned, it inter alia a punching, cold extrusion, cold working or the like understood, but in principle also other deformation possibilities are given, provided that a transformation is made possible, the production of at least initially open, allowed by sections of the contact pin edged opening.

According to FIGS. 1 to 4, the contact pin has a press-fit section 13 which has at least two contact legs 15, which are spaced apart from one another by at least one elongated opening 14 and curved outward in their central region. This press-fit reaches the hole 11 of a printed circuit board 12 during insertion as shown in FIG. 7, where it plastically deformed and thus ensures the desired contact with the circuit board. This contacting is to meet several requirements, which are essentially to be seen in the fact that a low Cl-resistance is guaranteed, no contact corrosion occurs, minimal press forces and maximum pull-out forces are present, a temperature resistance is ensured and preferably no chip formation during assembly established. In particular, the requirements for temperature resistance rise more and more and the compounds thus created should be durable, especially in the automotive sector even with larger vibrations. In addition, considering That the diameter of the holes of the circuit boards has a relatively large tolerance, while the contact pins and the contacting a small tolerance is required, it becomes clear which dimensioning limits arise in the production of such contact pins, especially if they produced by molding processes such as a punching process and this with increasingly smaller dimensions.

The contact pin 10 also has an insertion section 16 for insertion into the hole 11, which is formed according to FIGS. 2 and 3 by at least two elongate sections 17 of the contact pin, which abut one another during the insertion. The at least two sections 17, which border this opening starting from a material bridge lying in the insertion direction at the rear end of the elongate opening 14, adjoin the outwardly open, oblong opening 14 according to FIGS. 1 and 4 after the forming process. This open design thus creates a new scope for the design of the elongated opening. In this respect, only a few examples of the design of this opening are given below, which do not limit the invention further.

Preferably, the portions 17 are arranged substantially approximately parallel to each other, but only the formation of the outwardly open elongated opening 14 between them is essential. They may, if necessary, be connected together at their ends 17a to form a pin while enclosing the elongated opening 14. The connection does not actually have to take place at the last point of the end 17a, the person skilled in the art will rather choose this connection point in such a way that both a suitable insertion and correspondingly high pull-out forces are ensured. The compound can e.g. a mechanical connection, conceivable would be a common molding under positive locking, or a welded joint such. be a laser welding, but other connection possibilities, such as a riveting process also conceivable.

From the figures it is clear that the portions 17, which form the tines of a fork strictly speaking, form both the contact legs 15 of the press-in portion 13 and the pin-formed insertion portion 16. in principle can also be provided more than two sections 17. In the closed state, it is thus possible, among other things, to taper the elongate opening 14 in the insertion direction. As a result, in this region, which is important for the insertion movement and initially elastically deformed, there is the prerequisite that unnecessary material is not present there, which hinders precisely this insertion movement if a plastic deformation sets in too early.

On the edge of the oblong opening 14 projecting projections 18 are provided in the opening, which come into operative connection with one another during the plastic deformation of the contact pin 10. In principle, these projections can be arbitrarily shaped, in an embodiment according to Figures 3, 4 and 7, these projections are formed approximately opposite and come in the plastic deformation with each other, which can also be spoken of a positive engagement. These projections 18 on the one hand have the function of controlling the elastic-plastic behavior in the hole 11 via different hole diameters. The formations, which may also be referred to as a support element or pin, are provided to allow a better insertion of the contact and thus preferably to lie in a region which lies after insertion of the contact pin within the hole 11 of the circuit board. On the other hand, they can also be used, e.g. from Fig. 7 results in lying on the other side of the hole, pushed over area contribute to a kind of tilting movement, which makes this area wider than the lying in the hole 11 pressing area. This leads to increased extrusion forces.

In the embodiment of FIGS. 11 and 12, the projections 18 are in closed longitudinal opening 14 in the insertion direction in the opening 14 that they come to rest in the inserted state in the hole 11 and there increase the pull forces without contributing to increased chip formation during insertion. This leads to the arrangement shown in Fig. 11 and 12 after insertion of the contact pin 10 in the hole 11. However, other arrangements and configurations of the projections 18 are possible, for example in the front third of the opening 14 so that they through the hole 11 during insertion be pushed over. According to Fig. 11 and 12, the projections are effective even with different hole diameters of the circuit board. Fig. 11 shows the contact pin in a hole with a diameter of eg 1, 09 mm, while Fig. 12 shows the same contact pin in a hole with a diameter of 0.94 mm. In both cases, the projections build up sufficient holding forces.

According to Fig. 5 in conjunction with Fig. 8 or 9, the portions 17 may have an edge or bead embossing. This embossing can be a variable embossing 19, so that the embossing can also influence the press-in forces and extrusion forces. Preferably, the cross section of the sections 17 increases from the insertion section 16 to the press-in section 13. The contour of the embossing can be influenced in order to obtain a better osculation or contact surface.

The ends 17a of the sections 17 are tapered and rounded at their outer edges 20, which are usually pointing away from each other, to form an insertion pin. Preferably, the sections are at least in the region of the insertion section

16 symmetrically arranged to a through the elongated opening 14 center line. Again, other, not symmetrical configurations are possible because the skilled person can make both the elongated opening 14 and the sections 17 as required for the particular application, as long as an open shape of this opening is selected.

In the press-in section 13, as shown in FIG. 6, the outer edges 20 of the sections

17 notches 21 have to increase the holding forces in the hole 11 on.

The production of the contact pin 10 is initially carried out by forming the sections 17, so that they adjoin the elongated opening 14 which is open towards the outside in a fork-tooth manner. Following the sections 17 are bent together. They can then be connected to one another at the ends of the elongated opening 14, preferably at their ends 17a, or they can lie loosely together. This connection can be made mechanically or by welding. The deformation of the sections can be done in any way, preferably by punching, cold extrusion or cold forming. Preferably, the connection of the sections 17 takes place immediately after the forming, ie, for example, during the punching process by welding or laser welding, ie essentially in one operation or production step. In addition, the sections 17 can be provided with an embossment 19 or notches 21.

LIST OF REFERENCE NUMBERS

10 contact pin

11 holes

12 circuit board

13 press-in section

14 oblong opening

15 contact legs

16 introduction section

17 section

17a end

18 Forming

19 imprint

20 outer edge of 17

21 notch

Claims

claims

1. contact pin (10), with a contact and a connection region, wherein the contact pin of a formed material for pressing into a through-contacted hole (11) of a printed circuit board (12), the press-in portion (13) at least two by at least one elongated Opening (14) spaced from one another, in its central region outwardly curved contact legs (15) which come into contact with the hole of the printed circuit board with plastic deformation on the wall of the hole (11), wherein at least one insertion section (16) for insertion into the hole (11) is formed by at least two elongated, during insertion abutting portions (17) of the contact pin (10), wherein the portions (17) after the Umfor- mung process and before insertion into the hole (11) fork-like adjoining the outwardly open elongated opening (14), characterized in that at the edge of the elongated opening (14) at least one in the Öffnu ng protruding Anformung (18) is provided for forming support areas for controlling the elastic-plastic behavior in the hole diameter.

2. Contact pin according to claim 1, characterized in that the Anformung (18) for forming support elements lies in a range which is located after insertion of the contact pin within the hole (11) of the printed circuit board (12).

3. Contact pin according to claim 1 or 2, characterized in that the sections (17) at their ends (17 a) are bent together.

4. Contact pin according to one of the preceding claims, characterized in that the portions (17) preferably at their ends (17 a) to form a pin and under the enclosure of the elongated opening (14) connected to each other or are loose.

5. Contact pin according to one of the preceding claims, characterized in that the forming process is a punching operation, a cold extrusion and / or a cold deformation.

6. Contact pin according to one of the preceding claims, characterized in that form the portions (17), the contact legs (15) of the press-in portion (13) and the pin formed as an insertion portion (16).

7. Contact pin according to one of the preceding claims, characterized in that the preferably approximately opposite projections (18) are arranged on opposite sides of the opening and engage in the plastic deformation with each other.

8. Contact pin according to one of the preceding claims, characterized in that the sections (17) have an edge or bead embossing.

9. contact pin according to claim 8, characterized in that the embossment (19) is a variable embossing.

10. Contact pin according to one of the preceding claims, characterized in that the cross section of the sections (17) from the insertion section (16) to the press-in section (13) increases.

11. Contact pin according to one of the preceding claims, characterized in that the mutually facing away outer edges (20) of the at least preferably in the region of the insertion portions (16) symmetrically to a through the elongated opening (14) running center line shaped portions (17) for training an insertion tip are rounded.

12. Contact pin according to one of the preceding claims, characterized in that the outer edges (20) of the sections (17) in the press-in section (13) have notches (21).

13. A method for producing a contact pin (10) having a terminal and a contact area by forming, wherein the contact pin for pressing into a plated-through hole (11) of a printed circuit board (12) is determined and wherein the contact pin has a press-in portion (13) with at least two spaced apart by an elongated opening (14), in its central region outwardly curved contact legs (15) and an insertion portion (16) having at least two elongated, during insertion abutting portions (17), wherein the portions (17) during forming and prior to insertion into the hole (11), are formed so as to adjoin the outwardly open elongate opening (14) in a fork-tooth manner, characterized in that at least one projection (18) protruding into the opening at the edge of the oblong opening (14) ) is formed to form support areas that control the elastic-plastic behavior in the hole diameter.

14. The method according to claim 13, characterized in that the Anformung (18) is placed to form support elements in an area which is located after insertion of the contact pin within the hole (11) of the printed circuit board (12).

15. The method according to claim 13 or 14, characterized in that the sections (17) at their ends (17a) are bent together.

16. The method according to any one of claims 13 to 15, characterized in that the contact pin (10) is punched during cold forming, kaltfließgepresst and / or cold-formed.

17. The method according to any one of claims 13 to 16, characterized in that the punching of the elongated opening (14) with Anformung (18) and the connection of the sections (17) takes place immediately following one another in a single production step.

18. The method according to any one of claims 13 to 17, characterized in that the sections (17) are provided with an embossment (19).

19. The method according to any one of claims 13 to 18, characterized in that when forming on the outer edges (20) of the sections (17) notches (21) are generated.