Disk having an electric connecting element

Abstract

A disk having at least one electric connecting element is described. The disk has a substrate, and electrically conductive structure on a region of the substrate, a connecting element containing at least chromium-containing steel, and a layer of a soldering compound that electrically connects the connecting element to sub-regions of the electrically conductive structure.

Claims

1. A pane with at least one electrical connection element, comprising: a substrate for applying an electrically conductive structure on a region of the substrate, the substrate having a first coefficient of thermal expansion from 8×10−6/° C. to 9×10−6/° C., and a connection element of the at least one electrical connection element, wherein the connection element contains at least chromium-containing steel, wherein the connection element has a second coefficient of thermal expansion from 10×10−6/° C. to 11.5×10−6/° C., wherein the connection element contains at least 50 wt.-% to 89.5 wt.-% iron, 16 wt.-% to 20 wt.-% chromium, and one or more selected from the group of carbon, nickel, manganese, molybdenum, and titanium, wherein the difference between the first coefficient of thermal expansion of the substrate and the second coefficient of thermal expansion of the connection element is less than <5×10−6/° C.; and a layer of a lead-free solder material, wherein the layer of the lead-free solder material electrically connects the connection element to subregions of the electrically conductive structure, wherein the connection element includes edge regions and is bent upwards on the edge regions to form an intermediate space in which the solder material is present, the intermediate space being formed by the connection element and the electrically conductive structure, wherein a maximum outflow width of the solder material is negative so that the solder material is pulled back into the intermediate space, wherein the maximum outflow width is defined as a distance between outer edges of the connection element and a point of the solder material crossover at which the solder material drops below a layer thickness of 50 μm and wherein a first edge region of the edge regions includes a first end of a first inclined region of the first edge region connected to a flat central region of the first edge region and a free distal end of the first inclined region that is opposite the first end of the first inclined region, the first inclined region extending from the first end to the free distal end, the first inclined region having a lower surface extending upwards and facing the electrically conductive structure, the lower surface of the first inclined region extending upward from the first end to the free distal end, and wherein the solder material covers the lower surface of the first inclined region and is in direct contact with the lower surface of the first inclined region and with the electrically conductive structure.

2. The pane according to claim 1, wherein the substrate contains glass, polymers, or mixtures of glass and polymers.

3. The pane according to claim 2, wherein the glass is flat glass, float glass, quartz glass, borosilicate glass, or soda lime glass.

4. The pane according to claim 2, wherein the polymers are polyethylene, polypropylene, polycarbonate, or polymethyl methacrylate.

5. The pane according to claim 1, wherein the electrically conductive structure contains silver.

6. The pane according to claim 1, wherein a layer thickness of the solder material is less than 3.0×10−4 m.

7. The pane according to claim 1, wherein the solder material contains tin and i) bismuth, indium, zinc, iv) copper, v) silver, or compositions of i)-v).

8. The pane according to claim 7, wherein a proportion of tin in the solder material is 3 wt.-% to 99.5 wt.-% and a proportion of i) bismuth, indium, zinc, iv) copper, v) silver, or compositions of i) - v) is 0.5 wt.-% to 97 wt.-%.

9. The pane according to claim 1, wherein the connection element is coated with nickel, tin, copper, and/or silver.

10. The pane according to claim 9, wherein the connection element is coated with 0.1 μm to 0.3 μm nickel and/or 3 μm to 20 μm silver.

11. The pane according to claim 1, wherein the solder material forms a concave meniscus that extends from the lower surface of the first inclined region to the electrically conductive structure.

12. The pane according to claim 11, wherein the concave meniscus extends from the distal end to the electrically conductive structure.

13. The pane according to claim 1, wherein a height of the first edge region from the electrically conductive structure to the distal end is at most 400 μm.

14. The pane according to claim 1, wherein the flat central region is arranged in direct contact with the electrically conductive structure.

15. A method comprising: Providing the pane with the at least one electrical connection element according to claim 1; and using the pane with the at least one electrical connection element for vehicles with electrically conductive structures.

16. A method for production of a pane with at least one connection element, comprising: applying a solder material on at least one contact surface of a connection element of the at least one connection element with a fixed layer thickness, volume, shape, and arrangement; applying an electrically conductive structure on a substrate, having a first coefficient of thermal expansion from 8×10−6/° C. to 9×10−6/° C.; arranging the connection element with the solder material on the electrically conductive structure, wherein the connection element has a second coefficient of thermal expansion from 10×10−6/° C. to 11.5×10−6/° C., wherein the connection element contains at least 50 wt.-% to 89.5 wt.-% iron, 16 wt.-% to 20 wt.-% chromium, and one or more selected from the group of carbon, nickel, manganese, molybdenum, and titanium, and wherein the difference between the first coefficient of thermal expansion of the substrate and the second coefficient of thermal expansion of the connection element is less than <5×10−6/° C.; and soldering the connection element to subregions of the electrically conductive structure with a layer of a lead-free solder material, wherein the connection element includes edge regions and is bent upwards on the edge regions to form an intermediate space in which the solder material is present, the intermediate space being formed by the connection element and the electrically conductive structure, wherein a maximum outflow width of the solder material is negative so that the solder material is pulled back into the intermediate space, wherein the maximum outflow width is defined as a distance between outer edges of the connection element and a point of the solder material crossover at which the solder material drops below a layer thickness of 50 μm and wherein a first edge region of the edge regions includes a first end of a first inclined region of the first edge region connected to a flat central region of the first edge region and a free distal end of the first inclined region that is opposite the first end of the first inclined region, the first inclined region extending from the first end to the free distal end, the first inclined region having a lower surface extending upwards and facing the electrically conductive structure, the lower surface of the first inclined region extending upward from the first end to the free distal end, and wherein the solder material covers the lower surface of the first inclined region and is in direct contact with the lower surface of the first inclined region and with the electrically conductive structure.

Description

EXAMPLE

(1) Test specimens were produced with the pane 1 (thickness 3 mm, width 150 cm, and height 80 cm), the electrically conductive structure 2 in the form of a heating conductor structure, the electrical connection element 3 according to FIG. 1, the silver layer 5 on the contact surfaces 8 of the connection element 3, and the solder material 4. The material thickness of the connection element 3 was 0.8 mm. The contact surface 8 of the connection element 3 had a width of 4 mm and a length of 4 mm. The solder material 4 was applied in advance as a platelet with fixed layer thickness, volume, and shape on the contact surface 8 of the connection element 3. The connection element 3 was applied with the solder material 4 applied on the electrically conductive structure 2. The connection element 3 was soldered onto the electrically conductive structure 2 at a temperature of 200° C. and a processing time of 2 seconds. Outflow of the solder material 4 from the intermediate space between the electrical connection element 3 and the electrically conductive structure 2, which exceeded a layer thickness t of 50 μm, was observed only to a maximum outflow width of b=0.5 mm. The dimensions and compositions of the electrical connection element 3, the silver layer 5 on the contact surfaces 8 of the connection element 3, and the solder material 4 are found in Table 1. No critical mechanical stresses were observed in the pane 1 due to the arrangement of the solder material 4, predefined by the connection element 3 and the electrically conductive structure 2. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 was durably stable.

(2) Due to the capillary effect, the connection element 3 of FIG. 1a exhibited better adhesion between the connection element 3 and the substrate 1. Due to the arrangement of the solder material 4, no critical mechanical stresses were observed in the pane 1. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 was durably stable.

(3) With all specimens, it was possible to observe, with a temperature difference from +80° C. to −30° C., that no glass substrate 1 broke or showed damage. It was possible to demonstrate that, shortly after soldering, these panes 1 with the soldered connection element 3 were stable against a sudden temperature drop.

(4) TABLE-US-00001 TABLE 1 Components Material Example Connection Steel of material no. 1.4509 in element 3 accordance with EN 10 088-2 with the composition: Iron (wt.-%) 78.87 Carbon (wt.-%) 0.03 Chromium (wt.-%) 18.5 Titanium (wt.-%) 0.6 Niobium (wt.-%) 1 Manganese (wt.-%) 1 CTE (coefficient of thermal expansion) 10 (10.sup.−6/° C. for 0° C.-100° C.) Difference between CTE of the 1.7 connection element and substrate (10.sup.−6/° C. for 0° C.-100° C.) Thermal conductivity (W/mK for 25 20° C.) Thickness of the connection element  8.0 × 10.sup.−4 (m) Wetting layer 5 Silver (wt.-%) 100 Thickness of the layer (m)  7.0 × 10.sup.−6 Solder material 4 Tin (wt.-%) 40 Bismuth (wt.-%) 57 Silver (wt.-%) 3 Thickness of the solder layer in (m) 250 × 10.sup.−6 The thickness of the wetting layer and 257 × 10.sup.−6 the solder layer (m) Glass substrate 1 CTE (10.sup.−6/° C. for 0° C.-320° C.) 8.3 (Soda lime glass)

COMPARATIVE EXAMPLE

(5) The comparative example was carried out the same as the example. The difference resided in the use of a different material for the connection element 3. The connection element 3 was 100 wt.-% titanium. The connection element 3 thus had lower thermal conductivity, a lower coefficient of thermal expansion, and a smaller difference of the coefficients of thermal expansion between connection element 3 and substrate 1. The dimensions and components of the electrical connection element 3, the metal layer on the contact surfaces 8 of the connection element 3 and the solder material 4 are found in Table 2. The connection element 3 was soldered to the electrically conductive structure 2 in accordance with conventional methods by means of the solder material 4. With the outflow of the solder material 4 from the intermediate space between the electrical connection element 3 and the electrically conductive structure 2, which exceeded a layer thickness t of 50 μm, an average outflow width b=2 mm to 3 mm was obtained. The lower thermal conductivity of the material for the connection element resulted, in the comparative example, in a less uniform heating of the connection element during the soldering process.

(6) With a sudden temperature difference from +80° C. to −30° C., it was observed that the glass substrates 1 had major damage shortly after soldering.

(7) TABLE-US-00002 TABLE 2 Comparative Components Material example Connection Titanium (wt.-%) 100 element 3 CTE (coefficient of thermal expansion) 8.80 (10.sup.−6/° C. for 0° C.-100° C.) Difference between CTE of the 0.5 connection element and substrate (10.sup.−6/° C. for 0° C.-100° C.) Thermal conductivity (W/mK for 22 20° C.) Thickness of the connection element  8.0 × 10.sup.−4 (m) Wetting layer 5 Silver (wt.-%) 100 Thickness of the layer (m)  7.0 × 10.sup.−6 Solder material 4 Tin (wt.-%) 40 Bismuth (wt.-%) 57 Silver (wt.-%) 3 Thickness of the solder layer in (m) 250 × 10.sup.−6 The thickness of the wetting layer and 257 × 10.sup.−6 the solder layer (m) Glass substrate 1 CTE (10.sup.−6/° C. for 0° C.-320° C.) 8.3 (Soda lime glass)

(8) The differences from Tables 1 and 2 above and the advantages of the connection element 3 according to the invention are found in Table 3.

(9) TABLE-US-00003 TABLE 3 Embodiment according Compar- to the invention, ative Example example Material Steel of material no. 1.4509 in Titanium accordance with EN 10 088-2 Thermal conductivity 25 22 (W/mK for 20° C.) CTE (coefficient of thermal 10 8.8 expansion) of the connection element (10.sup.−6/° C. for 0° C.-100° C.) Difference between CTE 1.7 0.5 of the connection element and the substrate (10.sup.−6/° C. for 0° C.-100° C.)

(10) It was demonstrated that panes according to the invention with glass substrates 1 and electrical connection elements 3 according to the invention have better stability against sudden temperature differences. This result was unexpected and surprising for the person skilled in the art.

LIST OF REFERENCE CHARACTERS

(11) (1) Pane (2) Electrically conductive structure (3) Electrical connection element (4) Solder material (5) Wetting layer (6) Compensation member (7) Region of the electrical connection element 3 (8) Contact surface of the connection element 3 with the electrically conductive structure 2 (9) Plug connector (10) Indentation (11) Spacer (12) Contact bump (17) Welding region (18) Connection cable (19) Connecting tab (20) Notch (20′) Notch (22) Subregion of 2 (23) Curve b Maximum outflow width of the solder material t Limiting thickness of the solder material r Radius of curvature A-A′ Section line B-B′ Section line C-C′ Section line D-D′ Section line E-E′ Section line