ELECTRIC CONTACT ELEMENT FOR HIGH OPERATING VOLTAGES

Abstract

An electrical contact element for a connector has a metallic base body and a wear layer applied to the base body. The wear layer consists of an alloy having the components 82-91% by weight nickel, 9-18% by weight phosphorous, and 0-1% by weight further alloy elements.

Claims

1. Electrical contact element (11, 21) for a connector (10, 20), having a metallic base body (111, 211) and a wear layer (113, 213) applied to the base body (111, 211), characterised in that the wear layer (113, 213) consists of the following alloy elements: TABLE-US-00006 82-91% by weight nickel 9-18% by weight phosphorous 0-1% by weight further alloy elements wherein the sum of the alloy elements is 100% by weight.

2. Electrical contact element (11, 21) according to claim 1, characterised in that the wear layer (113, 213) is arranged directly on the base body (111, 211).

3. Electrical contact element (11, 21) according to claim 2, characterised in that the wear layer (113, 213) has a thickness (d.sub.113, d.sub.213) in the range of from 1.00 μm to 2.50 μm.

4. Electrical contact element (11, 21) according to claim 1, characterised in that a metallic intermediate layer (112, 212) is arranged between the base body (111, 211) and the wear layer (113, 213).

5. Electrical contact element (11, 21) according to claim 3, characterised in that the intermediate layer (112, 212) consists of the following alloy elements: TABLE-US-00007 99-100% by weight copper or nickel 0-1% by weight further alloy elements wherein the sum of the alloy elements is 100% by weight.

6. Electrical contact element (11, 21) according to claim 3 or 4, characterised in that the intermediate layer (112, 212) has a thickness (d.sub.112, d.sub.212) in the range of from 1.5 μm to 4.0 μm.

7. Electrical contact element (11, 21) according to one of claims 3 to 6, characterised in that the wear layer (113, 213) has a thickness (d.sub.113, d.sub.213) in the range of from 0.15 μm to 1.50 μm.

8. Electrical contact element (11, 21) according to one of claims 1 to 7, characterised in that a metallic and/or organic sliding layer (114, 214) is arranged on the wear layer (113, 213).

9. Electrical contact element (11, 21) according to claim 8, characterised in that the sliding layer (114, 214) contains an alloy that consists of the following alloy elements: TABLE-US-00008 98.5-100.0% by weight gold 0-0.5% by weight cobalt 0-1.0% by weight further alloy elements wherein the sum of the alloy elements is 100% by weight.

10. Electrical contact element (11, 21) according to claim 8 or 9, characterised in that the sliding layer (114, 214) contains at least one fluoropolymer and/or at least one fatty acid salt.

11. Electrical contact element (11, 21) according to one of claims 8 to 10, characterised in that the sliding layer (114, 214) has a thickness (d.sub.114, d.sub.214) in the range of from 0.05 μm to 0.25 μm.

12. Electrical contact element (11, 21) according to one of claims 1 to 11, characterised in that the base body (111, 211) consists of the following alloy elements: TABLE-US-00009 50-100% by weight copper 0-45% by weight zinc 0-5% by weight further alloy elements wherein the sum of the alloy elements is 100% by weight.

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 following description.

[0018] FIG. 1 shows a schematic longitudinal sectional view of an arrangement of two electrical connectors.

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

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

[0021] FIG. 4 shows a cross-sectional view of a contact region of two electrical contact elements according to other exemplary embodiments of the invention.

EXEMPLARY EMBODIMENTS OF THE INVENTION

[0022] FIG. 1 shows the schematic structure of a pair of connectors. A first connector 10 has an electrical contact element 11 in the form of a male element. This is surrounded by a first insulating body 12 made of a plastic. A second connector 20 has a second electrical contact element 21 in the form of a female element. This is surrounded by a second insulating body 22 made of a plastic. When the two connectors 10, 20 are plugged into each other in the manner shown, the second insulating body 22 is pushed into the first insulating body 12, wherein the first electrical contact element 11 slides 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 firmly onto the first contact element 11 by their spring force. Electrical transmission is then possible in a contact region 30 where the two contact elements 11, 21 make contact.

[0023] In electrical connectors 10, 20 that have contact elements 11, 21 according to the prior art, the structure of the contact elements 11, 21 depicted in FIG. 2 is present in the contact region 30. The first contact element 11 has a base body 111, an intermediate layer 112 arranged on the base body and a wear layer 113 arranged on the intermediate layer. The second contact element 21 has a base body 211, an intermediate layer 212 arranged on the base body 211, and a wear layer 213 arranged on the intermediate layer 212. The base bodies 111, 211, the intermediate layers 112, 212 and the wear layers 113, 213 each have the composition in percent by weight shown in Table 1:

TABLE-US-00001 TABLE 1 Base body Intermediate layer Wear layer 111, 211 112, 212 113, 213 Au 99.8 Co 0.2 Cu 100 Ni 100 Ru PTFE

[0024] In the present example, the intermediate 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 d.sub.113, d.sub.213 of 4 μm. The wear layers 113, 213 contact each other in the contact region 30. The large amount of gold-cobalt alloy, which is necessary for manufacturing the wear layers, results in the manufacture of the electrical contact elements 11, 21 being expensive.

[0025] FIG. 3 shows the structure of the electrical contact elements 11, 21 according to several exemplary embodiments of the invention, which can be used in the pair of connectors 10, 20 according to FIG. 1. In addition to the structure of the electrical contact elements 11, 21 already depicted in FIG. 2, consisting of base bodies 111, 211, intermediate layers 112, 212 and useful layers 113, 213, the contact elements 11, 21 according to these exemplary embodiments of the invention also have a sliding layer 114, 214 on their wear layers 113, 213. This results in no contacting of the wear layers 113, 213 occurring in the contact region 30, but rather a contacting of the sliding layers 114, 214. While the thickness of the intermediate layers 112, 212 in the exemplary embodiments of the invention corresponds to the thickness of the intermediate 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 only 0.65 μm in each case. This results in considerable material savings compared with the comparative example. In the embodiments according to the invention, the sliding layers 114, 214 each have a thickness d.sub.114, d.sub.214 of 0.10 μm. Each wear layer 113, 213 is thus thinner even together with its respective sliding layers 114, 214 than the wear layer 113, 213 in the comparative example.

[0026] In a first exemplary embodiment of the invention, the components of the contact elements 11, 21 have the composition in percent by weight listed in Table 2.

TABLE-US-00002 TABLE 2 Base body Intermediate layer Wear layer Sliding layer 111, 211 112, 212 113, 213 114, 214 Au 99.8 Co 0.2 Cu 100 Ni 100 89 P 11 PTFE

[0027] The intermediate layer, which consists of pure silver in the comparative example, thus consists of a nickel-phosphorous alloy in the first exemplary embodiment. This results in a cost saving, not only due to less metal used for the wear layer, but also due to the use of a lower-cost alloy.

[0028] The sliding layer 114, 214 consists of the same gold-cobalt alloy as the wear layer 113, 213 of the comparative example. Therefore, the sliding properties of the contact elements 11, 21 in the comparative example and in the first exemplary embodiment of the invention are equally good. However, the sliding layer 114, 214 is very thin compared to the wear layer 113, 213 of the comparative example, such that most of the expensive gold-cobalt alloy can be saved.

[0029] In a second exemplary embodiment of the electrical contact elements 11, 21, their components have the composition in percent by weight shown in Table 3:

TABLE-US-00003 TABLE 3 Base body Intermediate layer Wear layer Sliding layer 111, 211 112, 212 113, 213 114, 214 Au Co Cu 100 Ni 100 89 P 11 PTFE 100

[0030] Compared to the first exemplary embodiment, the metallic sliding layers 114, 214 have been replaced by organic sliding layers, each consisting of PTFE. It was found that by dispensing with an expensive noble metal in the third exemplary embodiment, excellent sliding properties of the contact elements 11, 21 can nevertheless be achieved, wherein the electrical transmission is nevertheless no worse than that of the electrical contact elements 11, 21 in the comparative example.

[0031] In a third exemplary embodiment of the invention, the intermediate layer 112, 212 is dispensed with, such that the contact elements 11, 21 have the structure depicted in FIG. 4, wherein the wear layer 113, 213 is arranged directly on the base body 111, 211 in each case. In contrast to the previous exemplary embodiments, the thickness d.sub.113, d.sub.213 of the wear layers 113, 213 is 1.50 μm in each case. The components of the contact elements 11, 21 have the composition listed in Table 4 in percent by weight.

TABLE-US-00004 TABLE 4 Base body Wear layer Sliding layer 111, 211 113, 213 114, 214 Au 99.8 Co 0.2 Cu 100 Ni 89 P 11 PTFE

[0032] By using a thicker wear layer than in the first and second exemplary embodiments of the invention, the contact elements 11, 21 can thus also be manufactured without using intermediate layers 112, 212. Although thicker wear layers 113, 213 are used here than in the first two exemplary embodiments, these are still significantly thinner than the wear layers 113, 213 of the comparative example.

[0033] In a fourth exemplary embodiment of the invention, the sliding layers 114, 214 of the contact elements 11, 21 of the third exemplary embodiment are also replaced by organic sliding layers, each of which consists of PTFE, just as the sliding layers 114, 214 of the first exemplary embodiment were also replaced by PTFE in the second exemplary embodiment. The components of the electrical contact elements 11, 21 then have the composition in percent by weight shown in Table 5:

TABLE-US-00005 TABLE 5 Base body Wear layer Sliding layer 111, 211 113, 213 114, 214 Au Co Cu 100 Ni 89 P 11 PTFE 100

[0034] All five described exemplary embodiments 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 for the contact elements 11, 21. They are suitable for electrical operating voltages of more than 150 V.