ELECTRICAL CONTACT ELEMENT

Abstract

An electrical contact element for a plug-in connector has a metallic base body and a wear layer applied to the base body. The wear layer consists of pure ruthenium or of an alloy with the components 50-100% w/w ruthenium, 0-30% w/w nickel, 0-20% w/w chromium, 0-20% w/w cobalt, 0-20% w/w platinum and 0-1% w/w further alloy elements. A metallic intermediary layer is arranged between the base body and the wear layer, which has a thickness ranging from 1.5 μm to 4.0 μm.

Claims

1. An electrical contact element for a plug-in connector, having a metallic base body, a metallic intermediary layer applied to the base body, which has a thickness ranging from 1.5 μm to 4.0 μm, and a wear layer applied to the intermediate layer, wherein the wear layer consists of the following alloy elements: TABLE-US-00005 50-100% w/w ruthenium 0-30% w/w nickel 0-20% w/w chromium 0-20% w/w cobalt 0-20% w/w platinum 0-1% w/w further alloy elements, wherein the sum of the alloy elements is 100% w/w, and wherein a metallic and/or organic slide layer is arranged on the wear layer.

2. The electrical contact element according to claim 1, wherein the wear layer has a thickness ranging from 0.15 μm to 1.50 μm.

3. The electrical contact element according to claim 1 wherein the intermediary layer consists of the following alloy elements: TABLE-US-00006 99-100% w/w copper or nickel 0-1% w/w further alloy elements, and wherein the sum of the alloy elements is 100% w/w.

4. The electrical contact element according to claim 1, wherein the slide layer contains an alloy which consists of the following alloy elements: TABLE-US-00007 98.5-100.0% w/w gold 0-0.5% w/w cobalt 0-1.0% w/w further alloy elements, and wherein the sum of the alloy elements is 100% w/w.

5. The electrical contact element to claim 1, wherein the slide layer contains at least one fluoropolymer and/or at least one fatty acid salt.

6. The electrical contact element according to claim 1, wherein the slide layer has a thickness from 0.05 μm to 0.25 μm.

7. The electrical contact element to claim 1, wherein the base body consists of the following alloy elements: TABLE-US-00008 50-100% w/w copper 0-45% w/w zinc 0-5% w/w further alloy elements, and wherein the sum of the alloy elements is 100% w/w.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Exemplary embodiments of the invention are depicted in the drawings and are explained in more detail in the description below.

[0018] FIG. 1 shows a schematic longitudinal sectional depiction of an arrangement made of two electrical plug-in connectors.

[0019] FIG. 2 shows a cross-sectional depiction of a contact region between two electrical contact elements in a comparative example.

[0020] FIG. 3 shows a cross-sectional depiction of a contact region of two electrical contact elements according to exemplary embodiments of the invention.

EXEMPLARY EMBODIMENTS OF THE INVENTION

[0021] FIG. 1 shows the schematic construction of a plug-in connector pair. A first plug-in connector 10 has an electrical contact element 11 in the form of a male element. This is surrounded by a first insulation body 12 made of a plastic. A second plug-in connector 20 has a second electrical contact element 21 in the form of a female element. This is surrounded by a second insulation body 22 made of a plastic. When the two plug-in connectors 10, 20 are plugged into each other in the manner depicted, then the second insulation body 22 is pushed into the first insulation body 12, wherein the first electrical contact element 11 is led into the second electrical contact element 21. In doing so, it bends the tongues of the second contact element 21 apart, which are then pressed fixedly onto the first contact element 11 by their spring force. In a contact region 30 in which the two contact elements 11, 21 are contacted, an electrical transmission is then possible.

[0022] In electrical plug connectors 10, 20, which have contact elements 11, 21 according to the prior art, the construction, depicted in FIG. 2, of the contact elements 11, 21 is present in the contact region 30. The first contact element 11 has a base body 111, an intermediary layer 112 arranged on the base body and a wear layer 113 arranged on the intermediary layer. The second contact element 21 has a base body 211, an intermediary layer 212 arranged on the base body 211 and a wear layer 213 arranged on the intermediary layer 212. The base bodies 111, 211, the intermediary layers 112, 212 and the wear layers 113, 213 each have the composition in weight percent specified in Table 1:

TABLE-US-00001 TABLE 1 Base body Intermediary layer Wear layer 111, 211 112, 212 113, 213 Ag 100 Au Co Cu 100 Ni 100 Ru PTFE

[0023] In the present example, the intermediary layers 112, 212 each have a thickness d.sub.112, d.sub.212 of 3 μm, and the wear layers 113, 213 each have a thickness of d.sub.113, d.sub.213 of 4 μm. The wear layers 113, 213 come into contact in the contact region 30, wherein it can lead to an attrition of silver. The large amount of silver necessary for the production of the wear layer leads to the production of the electrical contact elements 11, 21, being expensive.

[0024] FIG. 3 shows the construction of the electrical contact elements 11, 21 according to several exemplary embodiments of the invention, which can be used in the pair of plug-in connectors 10, 20 according to FIG. 1. In addition to the construction of the electrical contact elements 11, 21 already depicted in FIG. 2 made of base bodies 111, 211, intermediary layers 112, 212 and wear layers 113, 213, the contact elements 11, 21 each have an additional slide layer 114, 214 on their wear layers 113, 213 according to these exemplary embodiments of the invention. This leads to no contacting of the wear layers 113, 213 in the contact region 30, but instead there is a contacting of the slide layers 114, 214. While the thickness of the intermediary layers 112, 212 in the exemplary embodiments of the invention is in accordance with the thickness of the intermediary layers 112, 212 in the comparative example, the exemplary embodiments according to the invention make do with substantially thinner wear layers 113, 213, the thickness d.sub.113, d.sub.213 of which is respectively only 0.65 μm. This leads to a considerable material saving over the comparative example. In the exemplary embodiments according to the invention, the slide layers 114, 214 each have a thickness d.sub.114, d.sub.214 of 0.10 μm. Each wear layer 113, 213 itself, together with its respective slide layer 114, 214, is thus thinner than the wear layer 113, 213 in the comparative example.

[0025] In a first exemplary embodiment of the invention, the components of the contact elements 11, 21 have the composition in weight percent stated in Table 2.

TABLE-US-00002 TABLE 2 Base body Intermediary layer Wear layer Slide layer 111, 211 112, 212 113, 213 114, 214 Ag Au 99.8 Co 0.2 Cu 100 Ni 100 Ru 100 PTFE

[0026] The intermediary layer, which consists of pure silver in the comparative example, thus consists of pure ruthenium in the first exemplary embodiment. This leads to cost savings, not only because of less metal being used for the wear layer, but also because of the use of a more cost-effective metal. The slide layer consists of an alloy of gold and cobalt, which enables outstanding electrical transmission and, in addition, due to the softness of this alloy, has better slide properties than the silver used in the comparative example. However, the slide layer is so thin that it does not lead to any mentionable cost increase of the contact elements 11, 21 despite the noble metal used.

[0027] In a second exemplary embodiment of the electrical contact elements 11, 21 according to the invention, their components have the composition stated in Table 3 in weight percent:

TABLE-US-00003 TABLE 3 Base body Intermediary layer Wear layer Slide layer 111, 112 112, 212 113, 213 114, 214 Ag Au 99.8 Co 0.2 Cu 100 Ni 100 Ru 100 PTFE

[0028] The pure ruthenium of the wear layers 113, 213 according to the first exemplary embodiment have here been replaced by a ruthenium-nickel alloy. It has been established that the properties of the electrical contact elements according to the comparative example in relation to corrosion resistance and electrical transmission can also still be achieved or even exceeded when using such an alloy.

[0029] In a third exemplary embodiment of the electrical contact elements 11, 21, their components have the composition stated in Table 4 in weight percent:

TABLE-US-00004 TABLE 4 Base body Intermediary layer Wear layer Slide layer 111, 211 112, 212 113, 213 114, 214 Ag Au Co Cu 100 Ni 100 10 Ru 90 PTFE 100

[0030] In comparison to the first exemplary embodiment, the metallic slide layers 114, 214 have been replaced by organic slide layers, which each consist of PTFE. It has been established that, by dispensing with an expensive noble metal, outstanding slide properties of the contact elements 11, 21 can nevertheless be achieved in the third exemplary embodiment, wherein the electrical transmission is nevertheless not inferior to that of the electrical contact elements 11, 21 in the comparative example.

[0031] All three exemplary embodiments described of the electrical contact elements 11, 21 according to the invention enable a cost-effective replacement of the electrical contact elements 11, 21 according to the comparative example, without this leading to an impairment of the properties relevant to the contact elements 11, 21.