Pane having an electrical connection element

Abstract

A pane, includes a substrate, an electrically conductive structure on a region of the substrate, a layer of a solder material on a region of the electrically conductive structure, and at least two soldering points of the at least one electrical connection element on the solder material, wherein the at least two soldering points form at least one contact surface between the at least one electrical connection element and the electrically conductive structure, and a shape of the at least one contact surface has at least one segment of an oval, an ellipse, or a circle with a central angle α of at least 90°.

Claims

1. A pane, comprising: a substrate, the substrate having a first coefficient of thermal expansion from 8×10.sup.−6/° C. to 9×10.sup.−6/° C., at least one electrical connection element, an electrically conductive structure on a region of the substrate, a layer of a solder material on a region of the electrically conductive structure, wherein each of the at least one electrical connection element has a second coefficient of thermal expansion from 10×10.sup.−6/° C. to 13×10.sup.−6/° C., wherein a 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.sup.−6/° C., contains at least 50 wt. % to 89.5 wt. % iron, 16 wt. % to 20 wt. % chromium, and one or more elements selected from the group of carbon, nickel, manganese, molybdenum, and titanium, has at least two soldering points on the solder material, which form two contact surfaces, separated from each other, between the at least one electrical connection element and the electrically conductive structure, wherein the two contact surfaces are connected to each other via a surface of a bridge facing the substrate, and wherein a shape of each of the two contact surfaces has at least one segment of an oval, an ellipse, or a circle with a central angle α of at least 90°.

2. The pane according to claim 1, wherein the two contact surfaces are formed in a shape of a rectangle with two semicircles arranged on opposite sides.

3. The pane according to claim 1, wherein each of the two contact surfaces is formed in a shape of a circle or a circular segment with a central angle α of at least 180°.

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

5. The pane according to claim 1, wherein spacers are arranged on the two contact surfaces.

6. The pane according to claim 1, wherein each of the two soldering points is arranged on a contact bump.

7. The pane according to claim 1, wherein the solder material contains tin and i) bismuth, ii) indium, iii) 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, ii) indium, iii) 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 at least one electrical connection element is coated with nickel, tin, copper, or silver, or a mixture thereof.

10. A method for production of a pane with at least one electrical connection element according to claim 1, comprising: a) applying a solder material on at least one contact surface of the at least one electrical connection element as a platelet with a fixed layer thickness, volume, and shape, b) applying an electrically conductive structure to a region of a substrate, the substrate having a first coefficient of thermal expansion from 8×10.sup.−6/° C. to 9×10.sup.−6/° C., c) arranging the at least one electrical connection element with the solder material on the electrically conductive structure, wherein the at least one electrical connection element has a second coefficient of thermal expansion from 10×10.sup.−6/° C. to 13×10.sup.−6/° C., wherein the at least one electrical connection element contains at least 50 wt.-% to 89.5 wt.-% iron, 16 wt.-% to 20 wt.-% chromium, and one or more elements 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.sup.−6/° C., d) introducing energy to at least two soldering points, and e) soldering the at least one electrical connection element to the electrically conductive structure, thereby producing the pane, the pane including the substrate, the electrically conductive structure on the region of the substrate, a layer of a solder material on a region of the electrically conductive structure, and at least two soldering points of the at least one electrical connection element on the solder material, wherein the at least two soldering points form two contact surfaces between the at least one electrical connection element and the electrically conductive structure, each of the at least two soldering points being arranged on a contact bump, and a shape of each of the two contact surfaces has at least one segment of an oval, an ellipse, or a circle with a central angle α of at least 90°.

11. A method, comprising: using the pane with at least one electrical connection element according to claim 1, for vehicles with electrically conductive structures, preferably with heating conductors and/or antenna conductors.

12. The pane according to claim 3, wherein the central angle α is at least 220°.

13. The pane according to claim 4, wherein the glass is flat glass, float glass, quartz glass, borosilicate glass or soda lime glass.

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

15. The pane according to claim 9, wherein the at least one electrical connection element is coated with 0.1 μm to 0.3 μm nickel or 3 μm to 20 μm silver, or both 0.1 μm to 0.3 μm nickel and 3 μm to 20 μm silver.

Description

(1) The invention is explained in detail with reference to drawings and exemplary embodiments. The drawings are a schematic representation and not true to scale. The drawings do not restrict the invention in any way. They depict:

(2) FIG. 1a plan view of a first embodiment of the pane according to the invention,

(3) FIG. 1a a schematic representation of the heat distribution during the soldering process,

(4) FIG. 2a a cross-section A-A′ through the pane of FIG. 1,

(5) FIG. 2b a cross-section B-B′ through the pane of FIG. 1,

(6) FIG. 2c a cross-section C-C′ through the pane of FIG. 1,

(7) FIG. 3 a cross-section C-C′ through an alternative pane according to the invention,

(8) FIG. 4 a cross-section B-B′ through another alternative pane according to the invention,

(9) FIG. 5 a cross-section B-B′ through another alternative pane according to the invention,

(10) FIG. 6 a cross-section B-B′ through another alternative pane according to the invention,

(11) FIG. 7 a cross-section A-A′ through another alternative pane according to the invention,

(12) FIG. 8 a cross-section A-A′ through another alternative pane according to the invention,

(13) FIG. 8a a cross-section A-A′ through another alternative pane according to the invention,

(14) FIG. 9 a plan view of an alternative embodiment of the pane according to the invention,

(15) FIG. 9a a cross-section D-D′ through the pane of FIG. 9,

(16) FIG. 10 a plan view of an alternative embodiment of the connection element,

(17) FIG. 11 a plan view of another alternative embodiment of the connection element,

(18) FIG. 11a a cross-section E-E′ through the connection element of FIG. 11,

(19) FIG. 12 a plan view of another alternative embodiment of the connection element,

(20) FIG. 13 a plan view of another alternative embodiment of the connection element,

(21) FIG. 13a a cross-section F-F′ through the connection element of FIG. 13,

(22) FIG. 14 a detailed flow chart of the method according to the invention.

(23) FIG. 1, FIG. 2a, FIG. 2b, and FIG. 2c show, in each case, a detail of a heatable pane 1 according to the invention in the region of the electrical connection element 3. The pane 1 is a 3-mm-thick thermally prestressed single-pane safety glass made of soda lime glass. The pane 1 has a width of 150 cm and a height of 80 cm. An electrically conductive structure 2 in the form of a heating conductor structure 2 is printed on the pane 1. The electrically conductive structure 2 contains silver particles and glass frits. In the edge region of the pane 1, the electrically conductive structure 2 is widened to a width of 10 mm and forms a contact surface for the electrical connection element 3. In the edge region of the pane 1, there is also a covering serigraph (not shown). The connection element 3 consists of two foot regions 7 and 7′ that are connected to each other via the bridge 9. On the surfaces of the foot regions 7 and 7′ facing the substrate, two contact surfaces 8′ and 8″ are arranged. In the region of the contact surfaces 8′ and 8″, the solder material 4 effects a durable electrical and mechanical connection between the connection element 3 and the electrically conductive structure 2. The solder material 4 contains 57 wt.-% bismuth, 40 wt.-% tin, and 3 wt.-% silver. The solder material 4 is arranged through a predefined volume and shape completely between the electrical connection element 3 and the electrically conductive structure 2. The solder material 4 has a thickness of 250 μm. The electrical connection element 3 is made from steel of the material number 1.4509 in accordance with EN 10 088-2 (ThyssenKrupp Nirosta® 4509) with a coefficient of thermal expansion of 10.0×10.sup.−6/° C. Each of the contact surfaces 8′ and 8″ has the shape of a circular segment with a radius of 3 mm and a central angle α of 276°. The bridge 9 consists of three flat segments 10, 11, and 12. The surface of each of the two segments 10 and 12 facing the substrate encloses an angle of 40° with the surface of the substrate 1. The segment 11 is arranged parallel to the surface of the substrate 1. The electrical connection element 3 has a length of 24 mm. The two foot regions 7 and 7′ have a width of 6 mm; the bridge 9 has a width of 4 mm.

(24) On each of the surfaces 13 and 13′ of the foot regions 7 and 7′ facing away from the substrate, a contact bump 14 is arranged. The contact bumps 14 are shaped as hemispheres and have a height of 2.5×10.sup.−4 m and a width of 5×10.sup.−4 m. The centers of the contact bumps 14 are arranged vertical to the surface of the substrate above the circle centers of the contact surfaces 8′ and 8″. The soldering points 15 and 15′ are arranged at the points on the convex surface of the contact bumps 14 that have the greatest vertical distance from the surface of the substrate.

(25) Three spacers 19 are arranged on each of the contact surfaces 8′ and 8″. The spacers 19 are shaped as hemispheres and have a height of 2.5×10.sup.−4 m and a width of 5×10.sup.−4 m.

(26) Steel of the material number 1.4509 in accordance with EN 10 088-2 has good cold forming properties and good welding properties with all methods except gas welding. The steel is used for construction of sound suppressor systems and exhaust gas detoxification systems and is particularly suited for that due to its scaling resistance to more than 950° C. and corrosion resistance against the stresses occurring in the exhaust gas system.

(27) FIG. 1a depicts schematically a simplified representation of the heat distribution around the soldering points 15 and 15′ during the soldering process. The circular lines there are isotherms. The shape of the contact surfaces 8′ and 8″ of the connection elements 3 of FIG. 1 is adapted to the heat distribution. Thus, the solder material 4 in the region of the contact surfaces 8′ and 8″ is uniformly and completely fuzed.

(28) FIG. 3 depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2c, an alternative embodiment of the connection element 3 according to the invention. The electrical connection element 3 is provided on the surface facing the solder material 4 with a silver-containing coating 5. This prevents spreading of the solder material out beyond the coating 5 and limits the outflow width b. In another embodiment, an adhesion-promoting layer made, for example, of nickel and/or copper, can be located between the connection element 3 and the silver-containing layer 5. The outflow width b of the solder material 4 is less than 1 mm. No critical mechanical stresses are observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(29) FIG. 4 depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2c, another alternative embodiment of the connection element 3 according to the invention. The electrical connection element 3 contains, on the surface facing the solder material 4, a recess with a depth of 250 μm that forms a solder depot for the solder material 4. It is possible to completely prevent outflow of the solder material 4 from the intermediate space. The thermal stresses in the pane 1 are noncritical and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(30) FIG. 5 depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2c, another alternative embodiment of the connection element 3 according to the invention. The foot regions 7 and 7′ of the electrical connection element 3 are bent upward on the edge regions. The height of the upward bend of the edge region of the glass pane 1 is a maximum of 400 μm. This forms a space for the solder material 4. The predefined solder material 4 forms a concave meniscus between the electrical connection element 3 and the electrically conductive structure 2. It is possible to completely prevent outflow of solder material 4 from the intermediate space. The outflow width b, at roughly 0, is less than zero, largely because of the meniscus formed. The thermal stresses in the pane 1 are noncritical, and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(31) FIG. 6 depicts another alternative embodiment of the connection element 3 according to the invention with contact surfaces 8′ and 8″ in the shape of circular segments and bridge 9 shaped flat in sections. The connection element 3 contains an iron-containing alloy with a coefficient of thermal expansion of 8×10.sup.−6/° C. The material thickness is 2 mm. In the region of the contact surfaces 8′ and 8″ of the connection element 3, hat-shaped compensation members 6 are applied with chromium-containing steel of the material number 1.4509 in accordance with EN 10 088-2 (ThyssenKrupp Nirosta® 4509). The maximum layer thickness of the hat-shaped compensation members 6 is 4 mm. By means of the compensation members, it is possible to adapt the coefficients of thermal expansion of the connection element 3 to the requirements of the pane 1 and of the solder material 4. The hat-shaped compensation members 6 result in improved heat flow during the production of the solder connection 4. The heating occurs primarily in the center of the contact surfaces 8′ and 8″. It is possible to further reduce the outflow width b of the solder material 4. Because of the low outflow width b of <1 mm and the adapted coefficient of expansion, it is possible to further reduce the thermal stresses in the pane 1. The thermal stresses in the pane 1 are noncritical, and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(32) FIG. 7 depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2a, an alternative embodiment of the connection element 3 according to the invention. The bridge 9 is curved and has the profile of a circular arc with a radius of curvature of 12 mm. The thermal stresses in the pane 1 are noncritical and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(33) FIG. 8 depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2a, another alternative embodiment of the connection element 3 according to the invention. The bridge 9 is curved and changes its direction of curvature twice. Adjacent the foot regions 7 and 7′, the direction of curvature turns away from the substrate 1. Thus, there are no edges on the connections 16 and 16′ between the contact surfaces 8′ and 8″ and the bottom of the bridge 9. The bottom of the connection element 3 has a continuous progression. The thermal stresses in the pane 1 are noncritical and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(34) FIG. 8a depicts, in continuation of the exemplary embodiment of FIGS. 1 and 2a, another alternative embodiment of the connection element 3 according to the invention. The bridge 9 consists of two flat segments 22 and 23. The surface of each of the two segments 22 and 23 facing the substrate encloses an angle of 20° with the surface of the substrate 1. Together, the surfaces of the two segments 22 and 23 facing the substrate enclose an angle of 140°. The thermal stresses in the pane 1 are noncritical and a durable electrical and mechanical connection is provided between the connection element 3 and the pane 1 via the electrically conductive structure 2.

(35) FIG. 9 and FIG. 9a depict, in each case, a detail of another embodiment of the pane 1 according to the invention in the region of the electrical connection element 3. The connection element 3 contains steel of the material number 1.4509 in accordance with EN 10 088-2 (ThyssenKrupp Nirosta® 4509). The foot regions 7 and 7′ are connected to each other via the bridge 9. The bridge 9 consists of three flatly shaped segments 10, 11, and 12. Each of the contact surfaces 8′ and 8″ is shaped as a rectangle with semicircles arranged on opposite sides. The connection element 3 has a length of 24 mm. The bridge 9 has a width of 4 mm. The contact surfaces 8′ and 8″ are 4 mm long and 8 mm wide.

(36) A contact bump 14 is arranged on each of the surfaces 13 and 13′ of the foot regions 7 and 7′ turned away from the substrate 1. Each contact bump 14 is shaped as a rectangular solid with a length of 3 mm and a width of 1 mm, with the surfaces turned away from the substrate 1 curved convexly. The height of the contact bumps is 0.6 mm. The soldering points 15 and 15′ are arranged at the points on the convex surface of the contact bumps 14 that have the greatest vertical distance from the surface of the substrate. Two spacers 19 that are shaped as hemispheres with a radius of 2.5×10.sup.−4 m are arranged on each of the contact surfaces 8′ and 8″. No critical mechanical stresses were observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(37) FIG. 10 depicts a plan view of an alternative embodiment of the connection element 3 according to the invention. The foot regions 7 and 7′ are connected to each other via the bridge 9. The contact surfaces 8 and 8′ are formed as circular segments with a radius of 2.5 mm and a central angle α of 280°. The bridge 9 is curved. The width of the bridge becomes smaller starting from the connections 16 and 16′ to the contact surfaces 8 and 8′ in the direction of the center of the bridge. The minimum width of the bridge is 3 mm. No critical mechanical stresses were observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(38) In an alternative embodiment of the invention, the connection element 3 with the contour of FIG. 10 is not configured in the form of a bridge. Here, the connection element 3 is connected to the electrically conductive structure over its entire surface via a contact surface 8.

(39) FIG. 11 and FIG. 11a depict, in each case, a detail of another alternative embodiment of the connection element 3 according to the invention. The two foot regions 7 and 7′ are connected to each other via the bridge 9. Each contact surface 8′ and 8″ is shaped as a circular segment with a radius of 2.5 mm and a central angle α von 286°. The bridge 9 consists of two subelements. The subelements have, in each case, a curved subregion 17 and 17′ and a flat subregion 18 and 18′. The bridge 9 is connected to the foot region 7 via the subregion 17 and to the foot region 7′ via the subregion 17′. The directions of curvature of the subregions 17 and 17′ turn away from the substrate 1. The flat subregions 18 and 18′ are arranged perpendicular to the surface of the substrate and are in direct contact with each other. The contact bumps 14 are shaped as hemispheres with a radius of 5×10.sup.−4 m. The spacers 19 are shaped as hemispheres with a radius of 2.5×10.sup.−4 m. The connection element 3 has a length of 10 mm. The foot regions 7 and 7′ have a width of 5 mm; the bridge 9 has a width of 3 mm. The height of the bridge 9 from the surface of the substrate 1 is 3 mm. The height of the bridge 9 can preferably be between 1 mm and 5 mm. No critical mechanical stresses were observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(40) FIG. 12 depicts a plan view of another alternative embodiment of the connection element 3 according to the invention. The two foot regions 7 and 7′ are connected to each other via a curved bridge 9. Each contact surface 8′ and 8″ is shaped as a circle with a radius of 2.5 mm. The two connections 16 and 16′ between the foot regions 7 and 7′ and the bridge 9 are arranged completely on different sides of the direct connecting line between the circle centers of the contact surfaces 8′ and 8″. The projection of the bridge into the plane of the substrate surface is curved. In this case, the direction of curvature changes in the center of the bridge. Laterally, in the center of the bridge 9, are arranged two convexities opposite each other in the shape of circular segments with radii of 2 mm. The radii of the convexities can preferably be between 1 mm and 3 mm. The convexities can, for example, also have a rectangular shape with a preferred length and width from 1 mm to 6 mm. On the region of the bridge 9 that is delimited by the edges of the convexities, an electrically conductive material for connection to the onboard electrical system can, for example, be applied, by welding or crimping, for example. No critical mechanical stresses are observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(41) FIG. 13 and FIG. 13a depict, in each case, a detail of another alternative embodiment of the connection element 3 according to the invention. The connection element 3 is connected over its entire surface to the electrically conductive structure 2 via a contact surface 8. The contact surface 8 is shaped as a rectangle with semicircles arranged on opposite sides. The contact surface has a length of 14 mm and a width of 5 mm. The connection element 3 is bent upward all around in the edge region 20. The height of the edge region 20 from the glass pane 1 is 2.5 mm. The height of the edge region 20 can, in alternative embodiments of the invention, preferably be between 1 mm and 3 mm. An extension element 21 is arranged on the bent-up edge on one of the two straight sides of the connection element 3. The extension element 21 consists of a curved subregion and a flat subregion. The extension element 21 is connected to the edge region 20 of the connection element 3 via the curved subregion and the direction of curvature is toward the opposite side of the connection element 3. The extension element 21 has, in the plan view, a length of 11 mm and a width of 6 mm. The extension element 21 can preferably have a length between 5 mm and 20 mm, particularly preferably between 7 mm and 15 mm, and a width of 2 mm to 10 mm, particularly preferably from 4 mm to 8 mm. An electrically conductive material for connection to the onboard electrical system can, for example, be applied on the extension element 21, for example, by wielding, crimping, or in the form of a plug connector. No critical mechanical stresses are observed in the pane 1 due to the arrangement of the solder material 4. The connection of the pane 1 to the electrical connection element 3 via the electrically conductive structure 2 is durably stable.

(42) FIG. 14 depicts in detail a method according to the invention for production of a pane 1 with an electrical connection element 3. An example of the method according to the invention for production of a pane with an electrical connection element 3 is presented there. As the first step, it is necessary to portion the solder material 4 according to shape and volume. The portioned solder material 4 is arranged on the contact surface 8 or the contact surfaces 8′ and 8″ of the electrical connection element 3. The electrical connection element 3 is arranged with the solder material 4 on the electrically conductive structure 2. A durable connection of the electrical connection element 3 to the electrically conductive structure 2 and, thus, to the pane 1 takes place through the input of energy on the soldering points 15 and 15′.

EXAMPLE

(43) 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′ and 8″ of the connection element 3, and the solder material 4. The material thickness of the connection element 3 was 0.8 mm. The connection element 3 contained steel of the material number 1.4509 in accordance with EN 10 088-2 (ThyssenKrupp Nirosta® 4509). Three spacers 19 were arranged on each of the contact surfaces 8′ and 8″. Each soldering point 15 and 15′ was arranged on a contact bump 14. The solder material 4 was applied in advance as a platelet with fixed layer thickness, volume, and shape on the contact surfaces 8′ and 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=0.4 mm. The dimensions and compositions of the electrical connection element 3, the silver layer 5 on the contact surfaces 8′ and 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.

(44) 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.

(45) In addition, test specimens were executed with a second composition of the electrical connection element 3. Here, the connection element 3 contained an iron-nickel-cobalt alloy. The dimensions and compositions of the electrical connection element 3, the silver layer 5 on the contact surfaces 8′ and 8″ of the connection element 3, and the solder material 4 are found in Table 2. 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=0.4 mm was obtained. Here as well, it was possible to observe that, with a temperature difference from +80° C. to −30° C., 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.

(46) In addition, test specimens were executed with a third composition of the electrical connection element 3. Here, the connection element 3 contained an iron-nickel alloy. The dimensions and compositions of the electrical connection element 3, the silver layer 5 on the contact surfaces 8′ and 8″ of the connection element 3, and the solder material 4 are found in Table 3. 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=0.4 mm was obtained. Here as well, it was possible to observe that, with a temperature difference from +80° C. to −30° C., 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.

(47) 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.) 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)

(48) TABLE-US-00002 TABLE 2 Components Material Example Connection Iron (wt.-%) 54 element 3 Nickel (wt.-%) 29 Cobalt (wt.-%) 17 CTE (coefficient of thermal expansion) 5.1 (10.sup.−6/° C. for 0° C.-100° C.) Difference between CTE of the 3.2 connection element and substrate (10.sup.−6/° C. for 0° C.-100° 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)

(49) TABLE-US-00003 TABLE 3 Components Material Example Connection Iron (wt.-%) 65 element 3 Nickel (wt.-%) 35 CTE (coefficient of thermal expansion) 1.7 (10.sup.−6/° C. for 0° C.-100° C.) Difference between CTE of the 6.6 connection element and substrate (10.sup.−6/° C. for 0° C.-100° 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

(50) The comparative example was carried out the same as the example. The difference resided in the shape of the connection element. This was, according to the prior art, connected to the electrically conductive structure via a rectangular contact surface. The shape of the contact surface was not adapted to the profile of the heat distribution. No spacers were arranged on the contact surface. The soldering points 15 and 15′ were not arranged on contact bumps. The dimensions and components of the electrical connection element 3, of the metal layer on the contact surface of the connection element 3, and of the solder material 4 are found in Table 4. 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.

(51) 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.

(52) TABLE-US-00004 TABLE 4 Comparative 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 the substrate (10.sup.−6/° C. for 0° C.-100° 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)

(53) It was demonstrated that panes according to the invention with glass substrates 1 and electrical connection elements 3 according to the invention had better stability against sudden temperature differences.

(54) This result was unexpected and surprising for the person skilled in the art.

LIST OF REFERENCE CHARACTERS

(55) (1) Pane (2) Electrically conductive structure (3) Electrical connection element (4) Solder material (5) Wetting layer (6) Compensation member (7) Foot region of the electrical connection element 3 (7′) Foot region of the electrical connection element 3 (8) Contact surface of the connection element 3 (8′) Contact surface of the connection element 3 (8″) Contact surface of the connection element 3 (9) Bridge between the foot regions 7 and 7′ (10) Segment of the bridge 9 (11) Segment of the bridge 9 (12) Segment of the bridge 9 (13) Surface of the foot region 7 turned away from the substrate 1 (13′) Surface of the foot region 7′ turned away from the substrate 1 (14) Contact bump (15) Soldering point (15′) Soldering point (16) Connection of contact surface 8 and the bottom of the bridge 9 (16′) Connection the contact surface 8′ and the bottom of the bridge 9 (17) Subregion of the bridge 9 (17′) Subregion of the bridge 9 (18) Subregion of the bridge 9 (18′) Subregion of the bridge 9 (19) Spacer (20) Edge region of the connection element 3 (21) Extension element (22) Segment of the bridge 9 (23) Segment of the bridge 9 α Central angle of a circular segment of a contact surface 8′ b Maximum outflow width of the solder material t Limiting thickness of the solder material A-A′ Section line B-B′ Section line C-C′ Section line D-D′ Section line E-E′ Section line