WO2013087677A1

WO2013087677A1 - Spring contact, plug connector, and printed circuit board

Info

Publication number: WO2013087677A1
Application number: PCT/EP2012/075193
Authority: WO
Inventors: Achim Brenner
Original assignee: Harting Ag
Priority date: 2011-12-12
Filing date: 2012-12-12
Publication date: 2013-06-20
Also published as: DE102011056261B4; DE102011056261A1

Abstract

The invention relates to a spring contact for generating an electric connection. One end of the spring contact is fixed to a base shape, and the second end is resiliently inclined away from the base shape, conductive material being applied onto the surface of the spring contact in the form of at least one conductor path. The invention further relates to a spring contact, both ends of which are fixed to a base shape and the central region of which is resiliently inclined away from the base shape. In order to increase the durability of said spring contacts, at least one trench-shaped depression is introduced between the first end and the second end.

Description

Spring contact, connectors and printed circuit board

The invention relates to a spring contact, a connector and a printed circuit board.

Such spring contacts are needed to make a conductive connection between a conductor connected to the spring contact or a conductor track and a contact point. Spring contacts are used for example in connectors or on printed circuit boards.

EP 1 523 069 A1 shows an arcuate metallic contact spring which is arranged on a carrier plate. Metallic contact springs are usually produced in stamping and bending technology. This technology reaches its limits, especially for very small components. DE 197 17 882 A1 discloses a spring contact, which are made of a metallizable plastic. The metallizable plastic is provided in a chemical process with a conductive coating, such as a copper alloy.

In the case of multiple or permanent mechanical loading of the spring contact, the metallic, conductive coating is often detached from the surface and / or damaged. As a result, the conductive connection between the contact points can be interrupted.

As a general state of the art, reference is made to US 2007/0269997 A1, US 2005/0130462 A1, US 2002/0053463 A1 and US Pat. No. 7,649,145 B2. The object of the invention is to propose a spring contact, which is versatile and has a long life. The object is achieved by a spring contact according to claim 1 or 2, a connector according to claim 9 and a circuit board according to claim 10.

Advantageous embodiments of the invention are specified in the subclaims.

The spring contact is fixed at one end to a basic form, for example a printed circuit board or a plug connector, and is electrically conductively connected to a conductor track. The second end is inclined away from the basic shape and can be moved elastically towards or away from the basic shape. The spring contact has resilient properties.

An alternative embodiment of the spring contact is fixed at both ends to the basic shape. The middle area is resilient from the basic shape.

All embodiments of the spring contact consist of a metallizable plastic, which is at least partially provided with a conductive, metallic coating. The metallic coating will form a defined trace (with a trace width) on the surface of the spring contact. The conductive coating provides a conductive connection between a contact pad on the base mold and another contact pad which is contacted by the second end of the spring contact.

Advantageously, the metallizable plastic consists of a material that can be processed using the MID technique.

The MID (Molded Interconnection Devices) technology is mainly used to create complex, 3-dimensional trace structures on components that provide circuit board functionality.

Various methods are known in MID technology. The LDS method is described in the patent application DE 101 32 092 A1. There are, for example, liquid crystal polymers, so-called LCP (Liquid Crystal Polymer), used, which are molded by injection molding into components. Irradiation with a laser selectively activates the areas on which printed conductor structures are to be formed. Irradiation with the laser activates metal (eg palladium) that is chemically bound in the polymer, forming metal nuclei on the surface. In a chemical bath, a conductive metal layer is subsequently formed by electroless, chemical deposition on the metal nuclei formed. The first copper layer essentially serves the conductivity. To achieve even better electrical conductivity, even more metallic layers can be deposited. These additional layers also serve for mechanical stability and corrosion protection. Alternatively, the metallizable plastic can be made in a two-component injection molding process.

In the two-component MID technique, in the first process step, a metallizable thermoplastic, for example a palladium-doped plastic, is injected into a tool, whereby the surface to be provided with a conductive coating is imaged. In the second process step, the areas between and around these surfaces are encapsulated with a non-metallisable thermoplastic, whereby the workpiece - here the spring contact- receives its final shape.

Subsequently, the selective metallization of the surfaces to be provided with a conductive coating takes place in an electrolytic bath by means of a galvanic process. In this case, a metallic substance, preferably copper or a copper alloy, adheres to the doping. On the copper surface other metal compounds can be applied in further steps.

In a mechanical stress of a resilient plastic body with a metallic coating, it can, as already described above, come to damage to the coating. Therefore, according to the invention, at least one trench-shaped depression is provided in the plastic body through which the conductor runs at least partially.

From the plastic technology it is known that during the bending stress of a bar-shaped body, the outer plastic fibers are stretched or compressed, while the neutral fiber remains without deformation. The deepest point of the depression may run along the plane enclosing the neutral fiber. But it may also be sufficient if the deepest point of the depression is slightly above or below this level.

Advantageously, a second trench-shaped depressions is introduced between the first end and the second end of the spring contact. This is special advantageous if more complex bending lines are created by mechanical stress.

In an advantageous embodiment of the invention, the recess has substantially the shape of a cuboid or cuboid. The depression is ideally positioned at the same distance from the first and second end, ie approximately in the middle. In this area, the material experiences the strongest stress.

When the depression takes the form of a squaring, the surfaces averaging away from the bottom of the depression form an angle with an orthogonal of the bottom. Advantageously, this angle is between 5 ° and 75 °. Particularly preferably, the angle is between 15 ° and 45 °.

An embodiment of the invention is illustrated in the drawings and will be explained in more detail below. Show it:

Fig. 1 is a perspective view of a first embodiment of a

Spring contact

2 is a sectional view of the first embodiment of the spring contact,

Fig. 3 is a sectional view of a section of the spring contact in the region of the recess and

Fig. 4 is a schematic sectional view of an alternative embodiment of the spring contact.

FIG. 1 shows a perspective view of a first embodiment of a spring contact 1. The first end A of the spring contact 1 is fixed to a basic shape 2 (eg, a connector or a printed circuit board). The second end B is vertically spaced from this basic shape 2 and can be resiliently moved toward or away from it. As a rule, a force in the direction of the arrow 5 is exerted on the second end.

Along the surface of the spring contact, a conductor track 3 is introduced, which is connected at one end to a conductor track 3 on the base mold 2. The trace 3 at the second end B of the spring contact is later in contact with a contact point (not shown), for. As a connector or a printed circuit board brought. Between the first A and second end B of the spring contact 1, a recess 4 with a width 41 and a length 22 is introduced. In conjunction with Figure 2 it can be seen that the recess 4 has a substantially parallelepiped shape. The depth T of the recess is dependent on the neutral fiber of the selected material, as described above.

FIG. 3 shows an alternative form of recess which can be used in all the embodiments of the spring contact listed. The alternative depression has essentially the shape of a squaring. The surfaces 6, 7 which are angled away from the bottom 8 of the depression each include an angle σ 1, a 2 with an orthogonal 9 of the bottom 8.

FIG. 4 shows the schematic illustration of an alternative embodiment of the spring contact 1 '. The same parts bear the same reference numerals. Both ends A, B are fixed on the basic shape 2. Upon contact with a contact point, a force is exerted in the direction of the arrow 5 'on the central region of the spring contact V. The spring contact V comprises two recesses 4, which are each arranged between an end A, B and the point of application of the force. A conductor is not shown here for illustrative reasons. The neutral fiber of the (plastic) basic body represents that part of the plastic basic body which experiences a lower mechanical stress under a bending load. In other words, the portion of the body which substantially corresponds to the neutral phase remains substantially free of deformation. Thus, even the lowest mechanical forces act on the conductor track 3, which is located at the bottom of the depression 4. The length of the strip 3 within the recess 4 corresponds to the length 42 of the recess 4. The width 41 of the recess 4 is wider than the width 31 of the conductor 3. In other words, the conductor 3 does not fill the entire width 41 of the recess 4 off. On the left and / or right of the conductor track 3 within the depression 4, sections of the depression 4 can thus optionally be present, which are not covered by the conductor track 3. Thus, the conductor does not reach the edge of the depression. This is advantageous, since thus the mechanical stress on the conductor track is reduced.

The basic form 2 may be part of a connector or a printed circuit board or may be connected to a connector or a printed circuit board. The spring contact according to the invention for a connector or a printed circuit board has a recess with a first width and a conductor track with a second width. The conductor also extends along the spring contact through the depression. The first width of the recess can be greater than the second width of the conductor track. The recess preferably extends into the region of a neutral fiber of the spring contact. The neutral fiber represents that area of the spring contact which remains essentially free of deformation during a bending stress.

The spring contacts described above can be used according to the invention in connectors or on printed circuit boards. Thus, the invention also relates to a connector having at least one spring contact for generating an electrical connection. The spring contact is at one end to a basic shape, i. H. Part of the connector, fixed. The second end of the spring contact test is resiliently inclined away from the basic shape. On the surface of the spring contact is conductive material z. B. applied in the form of a conductor. Between the first and second end of the spring contact a trench-shaped depression is provided.

The invention also relates to a printed circuit board with at least one spring contact for generating an electrical connection. The spring contact is fixed at one end to a basic shape and a second end of the spring contact is resiliently inclined away from the basic shape. On the surface of the spring contact is conductive material z. B. applied in the form of a conductor. Between the first and second end of the spring contact a trench-shaped depression is provided. LIST OF REFERENCE NUMBERS

1 Spring contact A First end

2 basic form B second end

3 trace T depth

4 well or1 angle

5 arrow a2 angle

6 aloof area

7 angled surface

8 floor

9 Orthogonal

Claims

claims

Spring contact for generating an electrical connection,

• which is fixed at one end (A) to a basic shape (2),

• whose second end (B) of the basic shape (2) is resiliently inclined and

• on the surface of conductive material in the form of at least one conductor track (3) is applied with a conductor track width (31), wherein

• between the first end (A) and the second end (B) at least one trench-shaped recess (4) is introduced with a recess width (41),

• wherein the recess width (41) is greater than the line width (31).

Spring contact for generating an electrical connection,

• which is fixed to a basic shape (2) with first and second ends (A, B),

• whose central region is resiliently inclined away from the basic shape (2) and

wherein the groove width (41) is greater than the conductor track width (31).

3. spring contact according to claim 1 or 2, wherein

the spring contact (1, 1 ') is formed from a plastic which can be provided with a conductive coating by means of the MID technology.

4. spring contact according to claim 1, 2 or 3, wherein

between the first end (A) and the second end (B) two grave-shaped

Wells (4) are introduced.

Spring contact according to one of the preceding claims, wherein

• The recess (4) has substantially the shape of a cuboid or cuboid

• and is located approximately midway between the first (A) and second end (B).

6. spring contact according to one of the preceding claims, wherein

The angles (σ1, α2) enclosed by the angled surfaces (6, 7) of the ashlar with an orthogonal (9) of the base (8) are each between 5 ° and 75 °.

A spring contact according to claim 5, wherein

The angles (σ1, σ2) enclosed by the angled surfaces (6, 7) of the ashlar with an orthogonal (9) of the base (8) lie between 15 ° and 45 °.

8. spring contact according to one of claims 1 to 7, with

a neutral fiber (N),

wherein the depth (T) of the recess (4) extends substantially into the region of the neutral fiber (N).

9. connector with a spring contact according to one of claims 1 to 8,

wherein a part of the connector represents the basic shape (2).

Printed circuit board with a spring contact according to one of claims 1 to 8, wherein a part of the printed circuit board represents the basic shape (2).