EP2708092B1 - Pane having an electrical connection element - Google Patents

Description

The invention relates to a disc with an electrical connection element and an economical and environmentally friendly method for their production.

The invention further relates to a disc with an electrical connection element for vehicles with electrically conductive structures such as heating conductors or antenna conductors. The electrically conductive structures are usually connected via soldered electrical connection elements with the on-board electrical system. Due to different thermal expansion coefficients of the materials used, mechanical stresses occur during manufacture and during operation, which can load the disks and cause the disk to break.

Lead-containing solders have a high ductility, which can compensate occurring mechanical stresses between the electrical connection element and the disc by plastic deformation. However, due to the End of Life Vehicle Directive 2000/53 / EC within the EC lead-free solders must be replaced by lead-free solders. The Directive is collectively referred to as the ELV (End of Life Vehicles). The goal is to eliminate extremely problematic components from the products as a result of the massive expansion of disposable electronics. The substances involved are lead, mercury and cadmium. This includes, among other things, the enforcement of lead-free solders in electrical applications on glass and the introduction of appropriate replacement products for this purpose.

EP 1 942 703 A2 discloses an electrical connection element to panes of vehicles, wherein the difference in the coefficients of thermal expansion of the disc and electrical connection element <5 x 10 ^-6 / ° C, the connection element contains predominantly titanium and the contact surface between the connection element and electrically conductive structure is rectangular. In order to allow sufficient mechanical stability and processability, it is proposed to use a Lotmassenüberschuss. The excess of solder mass emerges from the gap between the connection element and the electrically conductive structure. The excess solder mass causes high mechanical stresses in the glass pane. These mechanical stresses eventually lead to breakage of the disc.

The object of the present invention is to provide a disk with an electrical connection element and an economical and environmentally friendly method for the production thereof, wherein critical mechanical stresses in the disk are avoided.

The pamphlets EP 1488972 A1 and EP 0023121 A1 each show a connection element with two solder joints, which form a contact surface between the connection element and an electrically conductive structure.

The object of the present invention is achieved by a device according to independent claim 1. Preferred embodiments will become apparent from the dependent claims.

• ein Substrat,
• eine elektrisch leitfähige Struktur auf einem Bereich des Substrats,
• eine Schicht einer Lotmasse auf einem Bereich der elektrisch leitfähigen Struktur und
• mindestens zwei Lötstellen des Anschlusselements auf der Lotmasse, wobei
• die Lötstellen mindestens eine Kontaktfläche zwischen dem Anschlusselement und der elektrisch leitfähigen Struktur ausbilden und
• die Form der Kontaktfläche mindestens ein Segment eines Ovals, einer Ellipse oder eines Kreises mit einem Mittelpunktswinkel von mindestens 90° aufweist.

The pane according to the invention with at least one electrical connection element comprises the following features:

• a substrate,
• an electrically conductive structure on a region of the substrate,
• a layer of a solder mass on a region of the electrically conductive structure and
• at least two solder joints of the connection element on the solder mass, wherein
• the solder joints form at least one contact surface between the connection element and the electrically conductive structure and
• the shape of the contact surface has at least one segment of an oval, an ellipse or a circle with a center angle of at least 90 °.

The midpoint angle of the segment is from 90 ° to 360 °, preferably from 140 ° to 360 °, for example from 180 ° to 330 ° or from 200 ° to 330 °. The shape of the contact surface between the connection element and the electrically conductive structure preferably has at least two semi-ellipses, particularly preferably two semicircles. Most preferably, the contact surface is formed as a rectangle with two arranged on opposite sides of the semicircles. In an alternative particularly preferred embodiment of the invention, the shape of the contact surface on two circle segments with center angle of 210 ° to 360 °. The shape of the contact surface can also comprise, for example, two segments of an oval, an ellipse or a circle, the center angle being from 180 ° to 350 °, preferably from 210 ° to 310 °.

In an advantageous embodiment of the invention, the solder joints form two separate contact surfaces between the connection element and the electrically conductive structure. Each contact surface is at the surface facing the substrate one of arranged two foot portions of the connection element. The foot areas are connected by a bridge. The two contact surfaces are connected to each other via the surface of the bridge facing the substrate. The shape of each of the two contact surfaces has at least one segment of an oval, an ellipse or a circle with a center angle of 90 ° to 360 °, preferably from 140 ° to 360 °. Each contact surface may have an oval, preferably an elliptical structure. Particularly preferably, each contact surface is formed as a circle. Alternatively, each contact surface is preferably formed as a circular segment with a center angle of at least 180 °, particularly preferably at least 200 °, very particularly preferably at least 220 °, and in particular at least 230 °. The circular segment may for example have a midpoint angle of 180 ° to 350 °, preferably from 200 ° to 330 °, particularly preferably from 210 ° to 310 °. In a further advantageous embodiment of the connecting element according to the invention, each contact surface is configured as a rectangle with two half-oval, preferably semi-ellipses, particularly preferably semi-circles arranged on opposite sides.

On the disc an electrically conductive structure is applied. The electrical connection element is electrically connected to a solder mass on portions with the electrically conductive structure.

The connection element is connected to the electrically conductive structure by soldering, for example resistance soldering, via the contact surface or the contact surfaces. In resistance soldering, two solder electrodes are used, each solder electrode being brought into contact with a solder joint of the terminal. During the soldering process, a current flows from a soldering electrode via the connecting element to the second soldering electrode. The contact between the soldering electrode and the connecting element preferably takes place over as small an area as possible. For example, the solder electrodes are designed as tips. The small contact surface causes a high current density in the region of the contact between soldering electrode and connecting element. The high current density leads to a heating of the contact area between the soldering electrode and the connection element. Starting from each of the two contact areas between soldering electrode and connecting element, the propagation of a heat distribution takes place. In the case of two point heat sources, the isotherms can be simplified as concentric circles around the solder joints. The exact shape of the heat distribution depends on the shape of the connection element dependent. The heating in the region of the contact surfaces between the connection element and the electrically conductive structure leads to the melting of the solder mass.

For example, according to the prior art, the connection element is preferably connected to the electrically conductive structure via a rectangular contact surface. Along the edges of a rectangular contact surface, temperature differences occur during the soldering process due to the heat distribution propagating from the solder joints. As a result, regions of the contact surface may exist in which the soldering material is not completely melted. These areas lead to poor adhesion of the connection element and to mechanical stresses in the pane.

The advantage of the invention lies in the shape of the contact surface or the contact surfaces between the connection element and the electrically conductive structure. The shape of the contact surfaces is rounded at least in a predominant region of the edges and preferably has circles or circle segments. The shape of the contact surfaces approximates the shape of the heat distribution around the solder joints during the soldering process. Therefore, no or only slight temperature differences occur along the edges of the contact surfaces during the soldering process. This leads to a uniform melting of the solder mass in the entire region of the contact surfaces between the connection element and the electrically conductive structure. This is particularly advantageous with regard to the adhesion of the connection element, the shortening of the duration of the soldering process and the avoidance of mechanical stresses in the pane. In particular, when using a lead-free solder mass, which can compensate less well due to their lower ductility compared to lead-containing solder masses mechanical stresses, there is a particular advantage.

The connection elements are in the plan view, for example, preferably 1 mm to 50 mm long and wide and more preferably 2 mm to 30 mm long and wide and most preferably 2 mm to 8 mm wide and 10 mm to 24 mm long.

For example, two contact surfaces interconnected by a bridge are preferably 1 mm to 15 mm long and wide, and more preferably 2 mm to 8 mm long and wide.

The solder mass emerges with an exit width of <1 mm from the gap between the connection element and the electrically conductive structure. In a preferred embodiment, the maximum exit width is preferably less than 0.5 mm and in particular about 0 mm. This is particularly advantageous with regard to the reduction of mechanical stresses in the disc, the adhesion of the connecting element and the saving of the solder.

The maximum exit width is defined as the distance between the outer edges of the connection element and the point of Lotmasseübertritts, at which the solder mass falls below a layer thickness of 50 microns. The maximum exit width is measured after the soldering process on the solidified solder mass.

A desired maximum exit width is achieved by a suitable choice of Lotmassenvolumen and perpendicular distance between the connection element and electrically conductive structure, which can be determined by simple experiments. The vertical distance between the connection element and the electrically conductive structure can be predetermined by a corresponding process tool, for example a tool with an integrated spacer.

The maximum exit width may also be negative, that is to say retracted into the intermediate space formed by the electrical connection element and the electrically conductive structure.

In an advantageous embodiment of the pane according to the invention, the maximum exit width in the intermediate space formed by the electrical connection element and the electrically conductive structure is withdrawn in a concave meniscus. For example, a concave meniscus is created by increasing the perpendicular distance between the spacer and conductive structure during the soldering process while the solder is still liquid.

The bridge between two foot areas of the connecting element according to the invention is preferably shaped in sections plan. Particularly preferably, the bridge consists of three planar sections. Plan means that the bottom of the connection element forms a plane. The angle between the surface of the substrate and the underside of each plane directly adjacent to a footer portion of the bridge is preferably < 90 °, more preferably between 1 ° and 85 °, most preferably between 2 ° and 75 ° and in particular between 3 ° and 60 °. The bridge is shaped such that each planar section adjoining a foot region is inclined in the direction away from the immediately adjacent foot region.

The advantage lies in the effect of the capillary effect between the electrically conductive structure and the sections of the bridge adjacent to the contact surfaces. The capillary effect is a consequence of the small distance between the electrically conductive structure and the sections of the bridge adjacent to the contact surfaces. The small distance results from the angle <90 ° between the surface of the substrate and the bottom of each directly to a foot area adjacent planar portion of the bridge. The desired distance between the connection element and the electrically conductive structure is set after the melting of the solder mass. Excess solder mass is controlled by the capillary effect in the sucked by the bridge and the electrically conductive structure volume. Characterized the Lotmasseübertritt is reduced at the outer edges of the connecting element and thus the maximum exit width. Thus, a reduction of the mechanical stresses in the disc is achieved.

In the sense of the definition of the maximum exit width, the edges of the contact surfaces to which the bridge is connected are not outer edges of the connection element.

The cavity defined by the electrically conductive structure and the bridge may be completely filled with solder. Preferably, the cavity is not completely filled with solder mass.

In a further advantageous embodiment of the invention, the bridge is curved. The bridge can have a single direction of curvature. In this case, the bridge preferably has the profile of an oval arc, particularly preferably the profile of an elliptical arc and very particularly preferably the profile of a circular arc. The radius of curvature of the circular arc is for example preferably from 5 mm to 15 mm with a length of the connecting element of 24 mm. The direction of curvature of the bridge can also change.

The bridge can also consist of at least two sub-elements, which are in direct contact with each other. The projection of the bridge into the plane of the substrate surface may also be curved. Preferably, this changes Curvature direction in the bridge center. The bridge does not have to have a constant width.

According to the invention, each of the two solder joints is arranged on a contact elevation. The contact elevations are arranged on the surface of the connection element facing away from the substrate. The contact elevations preferably contain the same alloy as the connection element. Each contact elevation is preferably formed convexly curved at least in the area facing away from the surface of the substrate. Each contact elevation is formed, for example, as a segment of an ellipsoid of revolution or as a spherical segment. Alternatively, the contact elevation can be formed as a cuboid, wherein the surface facing away from the substrate is convexly curved. The contact elevations preferably have a height of 0.1 mm to 2 mm, particularly preferably of 0.2 mm to 1 mm. The length and width of the contact elevations is preferably between 0.1 and 5 mm, very particularly preferably between 0.4 mm and 3 mm. The contact elevations can be designed as embossments. The contact elevations can be formed integrally with the connection element in an advantageous embodiment. The contact elevations can be formed, for example, by forming a connecting element with a flat surface in the initial state on the surface, for example by embossing or deep drawing. In this case, a corresponding depression can be produced on the contact elevation opposite surface of the connection element.

For soldering electrodes can be used, the contact side is formed flat. The electrode surface is brought into contact with the contact elevation. The electrode surface is arranged parallel to the surface of the substrate. The point on the convex surface of the contact elevation having the greatest perpendicular distance to the surface of the substrate is disposed between the electrode surface and the surface of the substrate. The contact area between the electrode surface and contact elevation forms the solder joint. The position of the solder joint is preferably determined by the point on the convex surface of the contact elevation, which has the greatest vertical distance from the surface of the substrate. The position of the solder joint is independent of the position of the soldering electrode on the connecting element. This is particularly advantageous in terms of a reproducible, even heat distribution during the soldering process. The heat distribution during the soldering process is determined by the position, the size, the arrangement and the geometry of the contact elevation. In an advantageous embodiment of the invention, at least two spacers are arranged on each of the contact surfaces of the connecting element. The spacers preferably contain the same alloy as the connection element. Each spacer is formed for example as a cube, as a pyramid, as a segment of an ellipsoid of revolution or as a spherical segment. The spacers preferably have a width of 0.5 × 10 ^-4 m to 10 × 10 ^-4 m and a height of 0.5 × 10 ^-4 m to 5 × 10 ^-4 m, more preferably of 1x 10 ^-4 m up to 3 x 10 ^-4 m. By the spacers the formation of a uniform solder layer is favored. This is particularly advantageous with regard to the adhesion of the connection element. The spacers may be formed integrally with the connection element. The spacers can be formed, for example, by forming a connecting element with flat initial contact surfaces on the contact surface, for example by embossing or deep drawing. In this case, a corresponding depression can be produced on the surface of the connection element which is opposite the contact surface.

Through the contact elevations and the spacers a homogeneous, uniformly thick and uniformly melted layer of the solder mass is achieved. As a result, mechanical stresses between the connection element and the disc can be reduced. This is particularly advantageous in the use of lead-free solder masses, which can compensate less well for mechanical stresses due to their lower ductility compared to lead-containing solder masses.

The substrate preferably contains glass, particularly preferably flat glass, float glass, quartz glass, borosilicate glass, soda-lime glass. In an alternative preferred embodiment, the substrate contains polymers, particularly preferably polyethylene, polypropylene, polycarbonate, polymethyl methacrylate and / or mixtures thereof.

The substrate has a first thermal expansion coefficient. The connection element has a second thermal expansion coefficient.

The first thermal expansion coefficient is preferably from 8 × 10 ^-6 / ° C to 9 × 10 ^-6 / ° C. The substrate preferably contains glass, which preferably has a thermal expansion coefficient of 8.3 × 10 ^-6 / ° C. to 9 × 10 ^-6 / ° C. in a temperature range from 0 ° C. to 300 ° C.

The connecting element according to the invention preferably contains at least one iron-nickel alloy, an iron-nickel-cobalt alloy or an iron-chromium alloy.

The connecting element according to the invention preferably contains at least 50 wt .-% to 89.5 wt .-% iron, 0 wt .-% to 50 wt .-% nickel, 0 wt .-% to 20 wt .-% chromium, 0 wt. -% to 20 wt .-% cobalt, 0 wt .-% to 1.5 wt .-% magnesium, 0 wt .-% to 1 wt .-% silicon, 0 wt .-% to 1 wt .-% carbon , 0% to 2% manganese, 0% to 5% molybdenum, 0% to 1% titanium, 0% to 1% by weight. % Niobium, 0 wt.% To 1 wt.% Vanadium, 0 wt.% To 1 wt.% Aluminum, and / or 0 wt.% To 1 wt.% Tungsten.

In an advantageous embodiment of the invention, the difference between the first and the second coefficient of expansion ≥ 5 x 10 ^-6 / ° C. The second coefficient of thermal expansion is preferably from 0.1 × 10 ^-6 / ° C. to 4 × 10 ^-6 / ° C., particularly preferably from 0.3 × 10 ^-6 / ° C. to 3 × 10 ^-6 / ° C. in a temperature range from 0 ° C to 300 ° C.

The connecting element according to the invention preferably contains at least 50% by weight to 75% by weight of iron, 25% by weight to 50% by weight of nickel, 0% by weight to 20% by weight of cobalt, 0% by weight. up to 1.5% by weight of magnesium, 0% by weight to 1% by weight of silicon, 0% by weight to 1% by weight of carbon and / or 0% by weight to 1% by weight of manganese ,

The connecting element according to the invention preferably contains chromium, niobium, aluminum, vanadium, tungsten and titanium in a proportion of 0 wt .-% to 1 wt .-%, molybdenum in a proportion of 0 wt .-% to 5 wt .-% and production-related additions.

The connecting element according to the invention preferably contains at least 55% by weight to 70% by weight of iron, 30% by weight to 45% by weight of nickel, 0% by weight to 5% by weight of cobalt, 0% by weight. up to 1% by weight of magnesium, 0% by weight to 1% by weight of silicon and / or 0% by weight to 1% by weight of carbon.

The connection element according to the invention preferably contains Invar (FeNi).

Invar is an iron-nickel alloy containing, for example, 36% by weight nickel (FeNi36). It is a group of alloys and compounds which have the property of having abnormally small or sometimes negative coefficients of thermal expansion in certain temperature ranges. Fe65Ni35 Invar contains 65% by weight iron and 35% by weight nickel. Up to 1% by weight of magnesium, silicon and carbon are usually alloyed to alter the mechanical properties. By alloying 5 wt .-% cobalt, the thermal expansion coefficient can be further reduced. One designation for the alloy is Inovco, FeNi33Co4.5 with an expansion coefficient (20 ° C to 100 ° C) of 0.55 x 10 ^-6 / ° C.

If an alloy such as Invar with a very low absolute thermal expansion coefficient of <4 x 10 ^-6 / ° C is used, the mechanical stresses are overcompensated by uncritical compressive stresses in the glass or by uncritical tensile stresses in the alloy.

In a further advantageous embodiment of the invention, the difference between the first and the second coefficient of expansion is <5 × 10 ^-6 / ° C. The small difference between the first and second coefficients of thermal expansion avoids critical stresses in the disk and provides better adhesion. The second coefficient of thermal expansion is preferably from 4 × 10 ^-6 / ° C. to 8 × 10 ^-6 / ° C., more preferably from 4 × 10 ^-6 / ° C. to 6 × 10 ^-6 / ° C. in a temperature range from 0 ° C to 300 ° C.

The connecting element according to the invention preferably contains at least 50% by weight to 60% by weight of iron, 25% by weight to 35% by weight of nickel, 15% by weight to 20% by weight of cobalt, 0% by weight. to 0.5 wt .-% silicon, 0 wt .-% to 0.1 wt .-% carbon and / or 0 wt .-% to 0.5 wt .-% manganese.

The connecting element according to the invention preferably contains Kovar (FeCoNi).

Kovar is an iron-nickel-cobalt alloy that has thermal expansion coefficients of usually about 5 x 10 ^-6 / ° C. The thermal expansion coefficient is thus lower than the coefficient of typical metals. The composition contains, for example, 54% by weight of iron, 29% by weight of nickel and 17% by weight of cobalt. In the field of microelectronics and microsystems technology, Kovar is therefore used as a housing material or as a submount used. Submounts lie on the sandwich principle between the actual carrier material and the material with usually much larger expansion coefficient. Kovar thus serves as a compensating element, which absorbs and reduces the caused by the different thermal expansion coefficients of the other materials thermo-mechanical stresses. In the same way, Kovar uses metal-to-glass penetrations of electronic components and material junctions in vacuum chambers.

The connecting element according to the invention preferably contains thermally treated iron-nickel and / or iron-nickel-cobalt alloys by annealing.

In a further advantageous embodiment of the invention, the difference between the first and the second expansion coefficient is also <5 x 10 ^-6 / ° C. The second thermal expansion coefficient is preferably from 9 × 10 ^-6 / ° C. to 13 × 10 ^-6 / ° C., particularly preferably from 10 × 10 ^-6 / ° C. to 11.5 × 10 ^-6 / ° C. in one Temperature range from 0 ° C to 300 ° C.

The connecting element according to the invention preferably contains at least 50% by weight to 89.5% by weight of iron, 10.5% by weight to 20% by weight of chromium, 0% by weight to 1% by weight of carbon, 0 Wt .-% to 5 wt .-% nickel, 0 wt .-% to 2 wt .-% manganese, 0 wt .-% to 2.5 wt .-% molybdenum and / or 0 wt .-% to 1 wt .-% titanium. The connection element may additionally contain admixtures of other elements, including vanadium, aluminum, niobium and nitrogen.

The connecting element according to the invention may also comprise at least 66.5% by weight to 89.5% by weight of iron, 10.5% by weight to 20% by weight of chromium, 0% by weight to 1% by weight of carbon , 0 wt .-% to 5 wt .-% nickel, 0 wt .-% to 2 wt .-% manganese, 0 wt .-% to 2.5 wt .-% molybdenum, 0 wt .-% to 2 wt .-% niobium and / or 0 wt .-% to 1 wt .-% titanium.

The connecting element according to the invention preferably contains at least 65% by weight to 89.5% by weight of iron, 10.5% by weight to 20% by weight of chromium, 0% by weight to 0.5% by weight of carbon , 0 wt .-% to 2.5 wt .-% nickel, 0 wt .-% to 1 wt .-% manganese, 0 wt .-% to 1 wt .-% molybdenum and / or 0 wt .-% bis 1% by weight of titanium.

The connecting element according to the invention may also comprise at least 73% by weight to 89.5% by weight of iron, 10.5% by weight to 20% by weight of chromium, 0% by weight to 0.5% by weight of carbon , 0 wt .-% to 2.5 wt .-% nickel, 0 wt .-% to 1 wt .-% manganese, 0 wt .-% to 1 wt .-% molybdenum, 0 wt .-% to 1 wt .-% niobium and / or 0 wt .-% to 1 wt .-% titanium.

The connecting element according to the invention preferably contains at least 75% by weight to 84% by weight of iron, 16% by weight to 18.5% by weight of chromium, 0% by weight to 0.1% by weight of carbon, 0 Wt .-% to 1 wt .-% manganese and / or 0 wt .-% to 1 wt .-% of titanium.

The connecting element according to the invention may also contain at least 78.5% by weight to 84% by weight of iron, 16% by weight to 18.5% by weight of chromium, 0% by weight to 0.1% by weight of carbon , 0 wt .-% to 1 wt .-% manganese, 0 wt .-% to 1 wt .-% of niobium and / or 0 wt .-% to 1 wt .-% titanium.

The connecting element according to the invention preferably contains a chromium-containing steel with a chromium content of greater than or equal to 10.5% by weight and a thermal expansion coefficient of 9 × 10 ^-6 / ° C. to 13 × 10 ^-6 / ° C. Other alloying constituents such as molybdenum, manganese or niobium lead to improved corrosion resistance or altered mechanical properties, such as tensile strength or cold workability.

The advantage of connecting elements made of chromium-containing steel compared to connection elements according to the prior art made of titanium lies in the better solderability. It results from the higher thermal conductivity of 25 W / mK to 30 W / mK compared to the thermal conductivity of titanium of 22 W / mK. The higher thermal conductivity leads to a more uniform heating of the connection element during the soldering process, whereby the punctiform formation of hot spots ("hot spots") is avoided. These points are starting points for later damage to the disc. This results in an improved adhesion of the connection element to the disc. Chromium-containing steel is also easy to weld. As a result, a better connection of the connection element to the on-board electrical system via an electrically conductive material, for example copper, by welding is possible. Due to the better cold workability, the connection element can also be better crimped with the electrically conductive material. Chromium-containing steel is also better available.

The electrically conductive structure according to the invention preferably has a layer thickness of 5 .mu.m to 40 .mu.m, particularly preferably from 5 .mu.m to 20 .mu.m, very particularly preferably from 8 .mu.m to 15 .mu.m and in particular from 10 .mu.m to 12 .mu.m. The electrically conductive structure according to the invention preferably contains silver, particularly preferably silver particles and glass frits.

The layer thickness of the solder according to the invention is preferably <3.0 × 10 ^-4 m.

The solder mass is preferably lead-free, so contains no lead. This is particularly advantageous with regard to the environmental compatibility of the disc with electrical connection element according to the invention. Lead-free solder masses typically have a lower ductility than lead-containing solder masses, so that mechanical stresses between the connection element and the pane can be compensated less well. However, it has been shown that critical mechanical stresses are significantly reduced by the connection element according to the invention. The solder mass according to the invention preferably contains tin and bismuth, indium, zinc, copper, silver or compositions thereof. The proportion of tin in the solder composition according to the invention is from 3 wt .-% to 99.5 wt .-%, preferably from 10 wt .-% to 95.5 wt .-%, particularly preferably from 15 wt .-% to 60 wt .-%. The proportion of bismuth, indium, zinc, copper, silver or compositions thereof in the solder composition according to the invention from 0.5 wt .-% to 97 wt .-%, preferably 10 wt .-% to 67 wt .-%, wherein the May be amount of bismuth, indium, zinc, copper or silver 0 wt .-%. The solder composition according to the invention may contain nickel, germanium, aluminum or phosphorus in a proportion of 0 wt .-% to 5 wt .-%. The solder composition of the present invention most preferably contains Bi40Sn57Ag3, Sn40Bi57Ag3, Bi59Sn40Ag1, Bi57Sn42Ag1, In97Ag3, Sn95.5Ag3.8Cu0.7, Bi67In33, Bi33In50Sn17, Sn77,2In20Ag2,8, Sn95Ag4Cu1, Sn99Cu1, Sn96,5Ag3,5 or mixtures thereof.

The connecting element according to the invention is preferably coated with nickel, tin, copper and / or silver. The connection element according to the invention is particularly preferably provided with an adhesion-promoting layer, preferably of nickel and / or copper, and additionally with a solderable layer, preferably of silver. The connection element according to the invention is very particularly preferably coated with 0.1 μm to 0.3 μm nickel and / or 3 μm to 20 μm silver. The connection element can be nickel-plated, tinned, copper-plated and / or silvered. Nickel and silver improve the ampacity and corrosion stability of the terminal and wetting with the solder mass.

The iron-nickel alloy, the iron-nickel-cobalt alloy or the iron-chromium alloy can also be welded, crimped or glued as a compensation plate on a connection element made of, for example, steel, aluminum, titanium, copper. As a bimetal, a favorable expansion behavior of the connection element can be achieved relative to the glass expansion. The balance plate is preferably hat-shaped.

The electrical connection element contains, on the surface aligned with the solder mass, a coating which contains copper, zinc, tin, silver, gold or alloys or layers thereof, preferably silver. This prevents spreading of the solder mass over the coating and limits the exit width.

The shape of the electrical connection element can form solder deposits in the intermediate space of connection element and electrically conductive structure. The solder deposits and wetting properties of the solder on the connecting element prevent the escape of the solder mass from the intermediate space. Lotdepots can be rectangular, rounded or polygonal configured.

The distribution of the solder heat and thus the distribution of the solder mass in the soldering process can be defined by the shape of the connection element. Lot mass flows to the warmest point. For example, the connection element may have a single or double hat shape in order to advantageously distribute the heat during the soldering process in the connection element.

The introduction of the energy in the electrical connection of electrical connection element and electrically conductive structure is preferably carried out with stamp, thermodes, bulb soldering, preferably laser soldering, hot air soldering, induction soldering, resistance soldering and / or with ultrasound.

1. a) Lotmasse auf der Kontaktfläche oder auf den Kontaktflächen des Anschlusselements als Plättchen mit festgelegter Schichtdicke, Volumen und Form aufgebracht wird,
2. b) eine elektrisch leitfähige Struktur auf einem Bereich eines Substrats aufgebracht wird,
3. c) das Anschlusselement mit der Lotmasse auf der elektrisch leitfähigen Struktur angeordnet wird,
4. d) an die Lötstellen Energie eingebracht wird und
5. e) das Anschlusselement mit der elektrisch leitfähigen Struktur verlötet wird.

The object of the invention is further achieved by a method for producing a pane according to the invention with at least one connection element, wherein

1. a) solder mass is applied on the contact surface or on the contact surfaces of the connection element as platelets with a defined layer thickness, volume and shape,
2. b) an electrically conductive structure is applied to a region of a substrate,
3. c) the connection element with the solder mass is arranged on the electrically conductive structure,
4. d) energy is introduced to the solder joints and
5. e) the connection element is soldered to the electrically conductive structure.

The solder mass is preferably applied beforehand to the connection elements, preferably as platelets with a defined layer thickness, volume, shape and arrangement on the connection element.

The connecting element can be welded or crimped, for example, with a sheet metal, a stranded wire or a braid of, for example, copper and connected to the on-board electrical system.

The connection element is preferably used in heating disks or in panes with antennas in buildings, in particular in automobiles, railways, aircraft or maritime vehicles. The connecting element serves to connect the conductive structures of the disc with electrical systems which are arranged outside the disc. The electrical systems are amplifiers, control units or voltage sources.

• Fig. 1 eine Draufsicht auf eine erste Ausgestaltung der erfindungsgemäßen Scheibe,
• Fig. 1a eine schematische Darstellung der Wärmeverteilung während des Lötvorgangs,
• Fig. 2a einen Schnitt A-A' durch die Scheibe gemäß Figur 1,
• Fig. 2b einen Schnitt B-B' durch die Scheibe gemäß Figur 1,
• Fig. 2c einen Schnitt C-C' durch die Scheibe gemäß Figur 1,
• Fig. 3 einen Schnitt C-C' durch eine alternative erfindungsgemäße Scheibe,
• Fig. 4 einen Schnitt B-B' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 5 einen Schnitt B-B' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 6 einen Schnitt B-B' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 7 einen Schnitt A-A' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 8 einen Schnitt A-A' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 8a einen Schnitt A-A' durch eine weitere alternative erfindungsgemäße Scheibe,
• Fig. 9 eine Draufsicht auf eine alternative Ausgestaltung der erfindungsgemäßen Scheibe,
• Fig. 9a einen Schnitt D-D' durch die Scheibe gemäß Figur 9,
• Fig. 10 eine Draufsicht auf eine alternative Ausgestaltung des Anschlusselements,
• Fig. 11 eine Draufsicht auf eine weitere alternative Ausgestaltung des Anschlusselements,
• Fig. 11a einen Schnitt E-E' durch das Anschlusselement gemäß Figur 11,
• Fig. 12 eine Draufsicht auf eine weitere alternative Ausgestaltung des Anschlusselements,
• Fig. 13 eine Draufsicht auf eine weitere alternative Ausgestaltung des Anschlusselements,
• Fig. 13a einen Schnitt F-F' durch das Anschlusselement gemäß Figur 13,
• Fig. 14 ein detailliertes Flussdiagramm des erfindungsgemäßen Verfahrens.

The invention will be explained in more detail with reference to a drawing and exemplary embodiments. The drawing is a schematic representation and not to scale. The drawing does not limit the invention in any way. Show it:

• Fig. 1 a plan view of a first embodiment of the disc according to the invention,
• Fig. 1a a schematic representation of the heat distribution during the soldering process,
• Fig. 2a a section AA 'through the disc according to FIG. 1 .
• Fig. 2b a section BB 'through the disc according to FIG. 1 .
• Fig. 2c a section CC 'through the disc according to FIG. 1 .
• Fig. 3 a section CC 'through an alternative disc according to the invention,
• Fig. 4 a section BB 'through a further alternative disc according to the invention,
• Fig. 5 a section BB 'through a further alternative disc according to the invention,
• Fig. 6 a section BB 'through a further alternative disc according to the invention,
• Fig. 7 a section AA 'by a further alternative disc according to the invention,
• Fig. 8 a section AA 'by a further alternative disc according to the invention,
• Fig. 8a a section AA 'by a further alternative disc according to the invention,
• Fig. 9 a plan view of an alternative embodiment of the disc according to the invention,
• Fig. 9a a section DD 'through the disc according to FIG. 9 .
• Fig. 10 a plan view of an alternative embodiment of the connecting element,
• Fig. 11 a plan view of a further alternative embodiment of the connection element,
• Fig. 11a a section EE 'through the connecting element according to FIG. 11 .
• Fig. 12 a plan view of a further alternative embodiment of the connection element,
• Fig. 13 a plan view of a further alternative embodiment of the connection element,
• Fig. 13a a section FF 'through the connecting element according to FIG. 13 .
• Fig. 14 a detailed flow chart of the method according to the invention.

Fig.1 . Fig. 2a . Fig. 2b and Fig. 2c each show a detail of a heated disc 1 according to the invention in the region of the electrical connection element 3. The disc 1 is a 3 mm thick thermally toughened single-pane safety glass made of soda lime glass. The disc 1 has a width of 150 cm and a height of 80 cm. An electrically conductive structure 2 in the form of a heat 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 Disc 1 is still an unillustrated Abdecksiebdruck. The connection element 3 consists of two foot areas 7 and 7 ', which are connected to one another via the bridge 9. Two contact surfaces 8 'and 8 "are arranged on the surfaces of the foot regions 7 and 7' facing towards the substrate. In the region of the contact surfaces 8 'and 8", the solder compound 4 effects a permanent electrical and mechanical connection between the connection element 3 and the electrically conductive structure 2. The solder mass 4 contains 57 wt .-% bismuth, 40 wt .-% tin and 3 wt .-% silver. The solder mass 4 is completely arranged between the electrical connection element 3 and the electrically conductive structure 2 by a predetermined volume and shape. The solder mass 4 has a thickness of 250 microns. The electrical connection element 3 consists of steel of the material number 1.4509 according to EN 10 088-2 (ThyssenKrupp Nirosta® 4509) with a thermal expansion coefficient of 10.0 × 10 ^-6 / ° C. Each of the contact surfaces 8 'and 8 "has the shape of a circle segment with a radius of 3 mm and a center angle α of 276 ° The bridge 9 consists of three plane sections 10, 11 and 12. The surface of each of the two sections facing the substrate 10 and 12 form an angle of 40 ° with the surface of the substrate 1. The portion 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 portions 7 and 7 'have a width of 6 mm, the bridge 9 has a width of 4 mm.

At each of the surfaces facing away from the substrate 13 and 13 'of the foot areas 7 and 7', a contact elevation 14 is arranged. The contact elevations 14 are formed as hemispheres and have a height of 2.5 × 10 ^-4 m and a width of 5 × 10 ^-4 m. The center points of the contact elevations 14 are arranged perpendicular to the surface of the substrate above the circle centers of the contact surfaces 8 'and 8 "The solder joints 15 and 15' are arranged at the points on the convex surface of the contact elevations 14 which are the greatest perpendicular distance to the surface of the contact elevations Substrate have.

Three spacers 19 are arranged on each of the contact surfaces 8 'and 8 "The spacers 19 are formed as hemispheres and have a height of 2.5 × 10 ^-4 m and a width of 5 × 10 ^-4 m.

Steel with the material number 1.4509 according to EN 10 088-2 is good cold forming and easy to weld with all processes except gas welding. The steel is used for the construction of silencer and exhaust gas decontamination systems and is due to the Scaling resistance up to more than 950 ° C and corrosion resistance against the stresses occurring in the exhaust system particularly suitable.

Fig. 1a schematically shows a simplified representation of the heat distribution around the solder joints 15 and 15 'during the soldering process. The circular lines are isotherms. The shape of the contact surfaces 8 'and 8 "of the connection element 3 from Fig. 1 the heat distribution is adjusted. As a result, the solder mass 4 is uniformly and completely melted in the area of the contact surfaces 8 'and 8 ".

Fig. 3 shows in continuation of the embodiment of FIGS. 1 and 2c an alternative embodiment of the connecting element 3 according to the invention. The electrical connection element 3 is provided on the surface oriented toward the solder mass 4 with a silver-containing coating 5. As a result, a spread of the solder mass over the coating 5 is prevented and the exit width b is limited. In a further embodiment, an adhesion-promoting layer, for example of nickel and / or copper, can be present between connection element 3 and silver-containing layer 5. The exit width b of the solder mass 4 is below 1 mm. Due to the arrangement of the solder mass 4, no critical mechanical stresses in the disk 1 are observed. The connection of the disc 1 to the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

Fig. 4 shows in continuation of the embodiment of FIGS. 1 and 2c a further alternative embodiment of the connecting element according to the invention 3. The electrical connection element 3 includes on the surface facing the solder mass 4 a recess with a depth of 250 microns, which forms a solder depot for the solder mass 4. An exit of the solder mass 4 from the gap can be completely prevented. The thermal stresses in the disc 1 are not critical and it is provided a permanent electrical and mechanical connection between the connection element 3 and the disc 1 via the electrically conductive structure 2.

Fig. 5 shows in continuation of the embodiment of FIGS. 1 and 2c a further alternative embodiment of the connecting element according to the invention 3. The foot portions 7 and 7 'of the electrical connection element 3 are bent at the edge regions. The height of the bend of the edge regions of the glass sheet 1 is a maximum of 400 microns. As a result, a space for the solder mass 4 is formed. The predetermined solder mass 4 forms between the electrical connection element 3 and the electrically conductive structure 2 a concave meniscus. An escape of solder mass 4 from the gap can be completely prevented. The exit width b is approximately zero, largely due to the meniscus formed below zero. The thermal stresses in the disc 1 are not critical and it is provided a permanent electrical and mechanical connection between the connection element 3 and the disc 1 via the electrically conductive structure 2.

Fig. 6 shows a further alternative embodiment of the connecting element 3 according to the invention with contact surfaces 8 'and 8 "in the form of circular segments and partially flat-shaped bridge 9. The connection element 3 contains an iron-containing alloy having a thermal expansion coefficient of 8 x 10 ^-6 / ° C. Die Materialdicke 2 mm .. In the area of the contact surfaces 8 'and 8 "of the connecting element 3, hat-shaped compensating bodies 6 with chromium-containing steel of the material number 1.4509 according to EN 10 088-2 (ThyssenKrupp Nirosta® 4509) are applied. The maximum layer thickness of the hat-shaped compensating body 6 is 4 mm. Due to the compensation body, the thermal expansion coefficients of the connection element 3 can be adapted to the requirements of the disc 1 and the solder mass 4. The hat-shaped compensating bodies 6 lead to an improved heat flow during the production of the soldered connection 4. The heating takes place above all in the center of the contact surfaces 8 'and 8 ", and the outlet width b of the soldering mass 4 can be further reduced because of the small outlet width b of <1 mm and the adjusted coefficient of expansion, the thermal stresses in the disc 1 can be reduced further The thermal stresses in the disc 1 are not critical and a permanent electrical and mechanical connection between the terminal element 3 and the disc 1 via the electrically conductive structure 2 is provided ,

Fig. 7 shows in continuation of the embodiment of FIGS. 1 and 2a an alternative embodiment of the connecting element according to the invention 3. 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 disc 1 are not critical and it is provided a permanent electrical and mechanical connection between the connection element 3 and the disc 1 via the electrically conductive structure 2.

Fig. 8 shows in continuation of the embodiment of FIGS. 1 and 2a a further alternative embodiment of the connecting element 3 according to the invention. The bridge 9 is curved and changes its direction of curvature twice. Adjacent to the foot regions 7 and 7 ', the direction of curvature away from the substrate 1. As a result, there are no edges at the connections 16 and 16 'between the contact surfaces 8' and 8 "and the underside of the bridge 9. The underside of the connection element 3 has a continuous course a permanent electrical and mechanical connection between the connection element 3 and the disc 1 via the electrically conductive structure 2 is provided.

Fig. 8a shows in continuation of the embodiment of FIGS. 1 and 2a a further alternative embodiment of the connecting element 3 according to the invention. The bridge 9 consists of two planar sections 22 and 23. The surface of each of the two sections 22 and 23 facing the substrate encloses an angle of 20 ° with the surface of the substrate 1. The walls facing the substrate surfaces of the two sections 22 and 23 form an angle of 140 ° with each other. The thermal stresses in the disc 1 are not critical and it is provided a permanent electrical and mechanical connection between the connection element 3 and the disc 1 via the electrically conductive structure 2.

Fig. 9 and Fig. 9a each show 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 according to EN 10 088-2 (ThyssenKrupp Nirosta® 4509). The foot areas 7 and 7 'are connected to each other via the bridge 9. The bridge 9 consists of three plan-shaped sections 10, 11 and 12. Each of the contact surfaces 8 'and 8 "is formed as a rectangle with semicircles arranged on opposite sides The connection element 3 has a length of 24 mm of 4 mm. The contact surfaces 8 'and 8 "are 4 mm long and 8 mm wide.

At each of the side facing away from the substrate 1 surfaces 13 and 13 'of the foot areas 7 and 7', a contact elevation 14 is arranged. Each contact elevation 14 is formed as a cuboid with a length of 3 mm and a width of 1 mm, wherein the surfaces facing away from the substrate 1 are formed convexly curved. The height of the contact elevations is 0.6 mm. The solder joints 15 and 15 'are located at the points on the convex surface of the contact elevations 14 which are the greatest perpendicular distance to the surface of the substrate. Arranged on each of the contact surfaces 8 'and 8 "are two spacers 19, which are formed as hemispheres with a radius of 2.5 × 10 ^-4 M. Due to the arrangement of the solder mass 4, no critical mechanical stresses are observed in the disk 1 Connection of the disc 1 with the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

Fig. 10 shows a plan view of an alternative embodiment of the connecting element 3 according to the invention. The foot areas 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 center 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 bridge center. The minimum width of the bridge is 3 mm. Due to the arrangement of the solder mass 4, no critical mechanical stresses in the disk 1 are observed. The connection of the disc 1 to the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

In an alternative embodiment of the invention, the connection element 3 with the contour FIG. 10 not designed like a bridge. The connection element 3 is connected over a contact surface 8 over its entire surface with the electrically conductive structure.

Fig. 11 and Fig. 11a each show a detail of a further alternative embodiment of the connecting element 3 according to the invention. The two foot regions 7 and 7 'are connected to one another via the bridge 9. Each contact surface 8 'and 8 "is formed as a circle segment with a radius of 2.5 mm and a center angle α of 286 ° .The bridge 9 consists of two subelements The subelements each have a curved subregion 17 and 17' and a planar subregion The bridge 9 is connected to the foot region 7 by the partial region 17 and to the foot region 7 'by the partial region 17' The curvature directions of the partial regions 17 and 17 'point away from the substrate 1. The planar partial regions 18 and 18 .. 'are arranged perpendicular to the surface of the substrate and are in direct contact with each other, the contact protrusions 14 are as hemispheres with a radius of 5 x 10 ^-4 m formed the spacers 19 are as hemispheres with a radius of 2.5 x 10 ^{- 4} m is formed. the connection element 3 has a length of 10 mm. the leg portions 7 and 7 'have a width of 5 mm, the bridge 9 has a width of 3 mm. the height of the bridge 9 of the Ob erfl of the Substrate 1 is 3 mm. The height of the bridge 9 may preferably be between 1 mm and 5 mm. Due to the arrangement of the solder mass 4, no critical mechanical stresses in the disk 1 are observed. The connection of the disc 1 to the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

Fig. 12 shows a plan view of a further alternative embodiment of the connecting element according to the invention 3. The two foot portions 7 and 7 'are connected to each other via a curved bridge 9. Each contact surface 8 'and 8 "is formed 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 completely on different sides of the direct connecting line between the circle centers of the Contact surfaces 8 'and 8 "arranged. The projection of the bridge into the plane of the substrate surface is curved. The direction of curvature changes in the middle of the bridge. In the middle of the bridge 9, two opposite bulges are arranged laterally in the form of circular segments with radii of 2 mm. The radii of the bulges may preferably be between 1 mm and 3 mm. The bulges may for example also have a rectangular shape with a preferred length and width of 1 mm to 6 mm. To the region of the bridge 9, which is bounded by the edges of the bulges, for example, an electrically conductive material for connection to the on-board electrical system can be attached, for example by welding or crimping. Due to the arrangement of the solder mass 4, no critical mechanical stresses in the disk 1 are observed. The connection of the disc 1 to the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

Fig. 13 and Fig. 13a each show a detail of a further alternative embodiment of the connecting element 3 according to the invention. The connecting element 3 is connected over the entire surface of the electrically conductive structure 2 via a contact surface 8. The contact surface 8 is formed as a rectangle with arranged on opposite sides of the semicircles. The contact surface has a length of 14 mm and a width of 5 mm. The connection element 3 is bent around in the edge region 20. The height of the edge region 20 of the glass sheet 1 is 2.5 mm. The height of the edge region 20 can preferably be between 1 mm and 3 mm in alternative embodiments of the invention. On one of the two straight sides of the connecting element 3, an extension element 21 is arranged on the bent-up edge. The extension element 21 consists of a curved portion and a planar portion. The Extension element 21 is connected by the curved portion with the edge region 20 of the connection element 3 and the direction of curvature faces the opposite side of the connection element 3. The extension member 21 has a length of 11 mm and a width of 6 mm in plan view. The extension element 21 may preferably have a length between 5 mm and 20 mm, more preferably between 7 mm and 15 mm and a width of 2 mm to 10 mm, particularly preferably from 4 mm to 8 mm. For example, an electrically conductive material for connection to the on-board electrical system can be attached to the extension element 21, for example by welding, crimping or in the form of a plug connection. Due to the arrangement of the solder mass 4, no critical mechanical stresses in the disk 1 are observed. The connection of the disc 1 to the electrical connection element 3 is permanently stable via the electrically conductive structure 2.

Fig. 14 shows in detail an inventive method for producing a disc 1 with electrical connection element 3. There, an example of the inventive method for producing a disc with an electrical connection element 3 is shown. As a first step, it is necessary to portion the solder mass 4 according to shape and volume. The portioned solder mass 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 mass 4 on the electrically conductive structure 2. A permanent connection of the electrical connection element 3 takes place the electrically conductive structure 2 and thereby with the disc 1 with energy input to the solder joints 15 and 15 '.

example

Test samples were made with the disc 1 (thickness 3 mm, width 150 cm and height 80 cm), the electrically conductive structure 2 in the form of a heat conductor structure, the electrical connection element 3 according to the FIG. 1 , the silver layer 5 on the contact surfaces 8 'and 8 "of the connection element 3 and the soldering compound 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 according to EN 10 088-2 (ThyssenKrupp Nirosta ® 4509) On each of the contact surfaces 8 'and 8 "three spacers 19 were arranged. Each solder joint 15 and 15 'was arranged on a contact elevation 14. The solder mass 4 was previously applied as platelets with a defined layer thickness, volume and shape on the contact surfaces 8 'and 8 "of the connection element 3. The connection element 3 was attached to the applied solder mass 4 on the electrically conductive structure 2. The connection element 3 was used in a Temperature of 200 ° C and a treatment time of 2 seconds soldered on the electrically conductive structure 2. An exit of the solder mass 4 from the gap between the electrical connection element 3 and the electrically conductive structure 2, which exceeded a layer thickness t of 50 microns, only 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 mass 4 are shown in Table 1. Due to the arrangement of the solder mass 4, predefined by the connection element 3 and the electrically conductive structure 2, no critical mechanical stresses were observed in the pane 1. The connection of the disc 1 with the electrical connection element 3 was permanently stable via the electrically conductive structure 2.

For all samples it could be observed at a temperature difference of +80 ° C to -30 ° C that no glass substrate 1 broke or showed damage. It could be shown that shortly after soldering these discs 1 with soldered connection element 3 were stable against sudden temperature drop.

Furthermore, test samples were performed with a second composition of the electrical connection element 3. The connecting 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 mass 4 are shown in Table 2. When the solder mass 4 emerged 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 exit width b = 0.4 mm was obtained. Again, it could be observed that at a temperature difference of +80 ° C to -30 ° C no glass substrate 1 broke or had damage. It could be shown that shortly after soldering these disks 1 with soldered connection element 3 were stable against sudden temperature drop.

Furthermore, test samples having a third composition of the electrical connection element 3 were performed. The connecting 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 mass 4 are shown in Table 3. When the solder mass 4 emerges from the gap between the electrical connection element 3 and the electrically conductive Structure 2, which exceeded a layer thickness t of 50 μm, was given an average exit width b = 0.4 mm, and it could be observed that at a temperature difference of +80 ° C to -30 ° C no glass substrate 1 broke or damaged It could be shown that shortly after soldering these discs 1 with soldered connection element 3 were stable against sudden temperature drop. Table 1 ingredients material example Connection element 3 Steel of material number 1.4509 according to EN 10 088-2 with the composition: Iron (wt.%) 78.87 Carbon (wt%) 0.03 Chromium (wt.%) 18.5 Titanium (% by weight) 0.6 Niobium (% by weight) 1 Manganese (wt.%) 1 CTE (10 ^-6 / ° C for 0 ° C - 100 ° C) 10 Difference between CTE connection element and substrate (10 ^-6 / ° C for 0 ° C - 100 ° C) 1.7 Thickness of the connection element (m) 8.0 x 10 ^-4 Wetting layer 5 Silver (wt.%) 100 Thickness of the layer (m) 7.0x10 ^-6 Lot mass 4 Tin (wt%) 40 Bismuth (% by weight) 57 Silver (wt.%) 3 Thickness of the solder layer in (m) ^{250x10 -6} The thickness of the wetting layer and the solder layer (m) 257 x 10 ^-6 Glass substrate 1 (Soda lime glass) CTE (10 ^-6 / ° C for 0 ° C - 320 ° C) 8.3 ingredients material example Connection element 3 Iron (wt.%) 54 Nickel (wt.%) 29 Cobalt (% by weight) 17 CTE (10 ^-6 / ° C for 0 ° C - 100 ° C) 5.1 Difference between CTE connection element and substrate (10 ^-6 / ° C for 0 ° C - 100 ° C) 3.2 Thickness of the connection element (m) 8.0 x 10 ^-4 Wetting layer 5 Silver (wt.%) 100 Thickness of the layer (m) 7.0x10 ^-6 Lot mass 4 Tin (wt%) 40 Bismuth (% by weight) 57 Silver (wt.%) 3 Thickness of the solder layer in (m) ^{250x10 -6} The thickness of the wetting layer and the solder layer (m) 257 x 10 ^-6 Glass substrate 1 (Soda lime glass) CTE (1 0 ^-6 / ° C for 0 ° C - 320 ° C) 8.3 ingredients material example Connection element 3 Iron (wt.%) 65 Nickel (wt.%) 35 CTE (10 ^-6 / ° C for 0 ° C - 100 ° C) 1.7 Difference between CTE connection element and substrate (10 ^-6 / ° C for 0 ° C - 100 ° C) 6.6 Thickness of the connection element (m) 8.0 x 10 ^-4 Wetting layer 5 Silver (wt.%) 100 Thickness of the layer (m) 7.0x10 ^-6 Lot mass 4 Tin (wt%) 40 Bismuth (% by weight) 57 Silver (wt.%) 3 Thickness of the solder layer in (m) ^{250x10 -6} The thickness of the wetting layer and the solder layer (m) 257 x 10 ^-6 Glass substrate 1 (Soda lime glass) CTE (1 0 ^-6 / ° C for 0 ° C - 320 ° C) 8.3

Comparative example

The comparative example was carried out in the same way as the example. The difference was in the shape of the connection element. This was connected to the prior art via a rectangular contact surface with the electrically conductive structure. The shape of the contact surface was not adapted to the profile of heat distribution. No spacers were placed on the contact surface. The solder joints 15 and 15 'were not arranged on contact elevations. The dimensions and components of the electrical connection element 3, the metal layer on the contact surface of the connection element 3 and the solder mass 4 are shown in Table 4. The connection element 3 was soldered to the electrically conductive structure 2 by conventional methods by means of the solder mass 4. When the solder mass 4 emerged 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 exit width b = 2 mm to 3 mm was obtained.

At a sudden temperature difference of +80 ° C to -30 ° C, it was observed that the glass substrates 1 were mostly damaged shortly after soldering. Table 4 ingredients material Comparative example Connection element 3 Steel of material number 1.4509 according to EN 10 088-2 with the composition: Iron (wt.%) 78.87 Carbon (wt%) 0.03 Chromium (wt.%) 18.5 Titanium (% by weight) 0.6 Niobium (% by weight) 1 Manganese (wt.%) 1 CTE (10 ^-6 / ° C for 0 ° C - 100 ° C) 10 Difference between CTE of the terminal and the substrate (10 ^-6 / ° C for 0 ° C - 100 ° C) 1.7 Thickness of the connection element (m) 8.0 x 10 ^-4 Wetting layer 5 Silver (wt.%) 100 Thickness of the layer (m) 7.0x10 ^-6 Lot mass 4 Tin (wt%) 40 Bismuth (% by weight) 57 Silver (wt.%) 3 Thickness of the solder layer in (m) ^{250x10 -6} The thickness of the wetting layer and the solder layer (m) 257 x 10 ^-6 Glass substrate 1 (Soda lime glass) CTE (10 ^-6 / ° C for 0 ° C - 320 ° C) 8.3

It has been found that panes according to the invention with glass substrates 1 and electrical connection elements 3 according to the invention have a better stability against sudden temperature differences.

This result was unexpected and surprising to the skilled person.

LIST OF REFERENCE NUMBERS

(1)

disc

(2)

Electrically conductive structure

(3)

Electrical connection element

(4)

solder mass

(5)

Wetting layer

(6)

compensation body

(7)

Foot area of the electrical connection element 3

(7 ')

Foot area of the electrical connection element 3

(8th)

Contact surface of the connection element 3

(8th')

Contact surface of the connection element 3

(8th")

Contact surface of the connection element 3

(9)

Bridge between the foot areas 7 and 7 '

(10)

Section of the bridge 9

(11)

Section of the bridge 9

(12)

Section of the bridge 9

(13)

surface of the foot region 7 facing away from the substrate 1

(13 ')

facing away from the substrate 1 surface of the foot region 7 '

(14)

Contact survey

(15)

soldered point

(15 ')

soldered point

(16)

Connection of contact surface 8 and the underside of the bridge 9

(16 ')

Connection of contact surface 8 'and the underside of the bridge. 9

(17)

Part of the bridge 9

(17 ')

Part of the bridge 9

(18)

Part of the bridge 9

(18 ')

Part of the bridge 9

(19)

spacer

(20)

Edge region of the connection element 3

(21)

extension element

(22)

Section of the bridge 9

(23)

Section of the bridge 9

α

Center point angle of a circle segment of a contact surface 8 '

b

maximum exit width of the solder mass

t

Limit thickness of the solder mass

A-A '

intersection

B-B '

intersection

C-C '

intersection

D-D '

intersection

E-E '

intersection

F-F '

intersection

Claims (14)

1. A pane with at least one electrical connection element, comprising:

   - a substrate (1),

   - an electrically conductive structure (2) on a region of the substrate (1),

   - a layer of a solder material (4) on a region of the electrically conductive structure (2), and

   - at least two soldering points (15,15') of the connection element (3) on the solder material (4), wherein

   - the soldering points (15,15') form at least one contact surface (8) between the connection element (3) and the electrically conductive structure (2), and

   - the shape of the contact surface (8) has at least one segment of an oval, of an ellipse, or of a circle with a central angle α of at least 90°,

   wherein each of the two soldering points (15, 15') is arranged on a contact bump (14) and
   wherein the contact bumps (14) are arranged on a surface (13, 13') of the connection element (3) facing away from the substrate
2. Pane according to claim 1, wherein

   - the soldering points (15,15') form two contact surfaces (8',8"), separated from each other, between the connection element (3) and the electrically conductive structure (2),

   - the two contact surfaces (8',8") are connected to each other via the surface of a bridge (9) facing the substrate (1), and

   - the shape of each of the two contact surfaces (8',8") has at least one segment of an oval, of an ellipse, or of a circle with a central angle α of at least 90°.
3. Pane according to claim 1 or 2, wherein the contact surface (8) or the contact surfaces (8',8") are formed in the shape of a rectangle with two semicircles arranged on opposite sides.
4. Pane according to claim 2, wherein each contact surface (8', 8") is formed in the shape of a circle or a circular segment with a central angle α of at least 180°, preferably at least 220°.
5. Pane according to one of claims 1 through 4, wherein the substrate (1) contains glass, preferably flat glass, float glass, quartz glass, borosilicate glass, soda lime glass, or polymers, preferably polyethylene, polypropylene, polycarbonate, polymethyl methacrylate, and / or mixtures thereof.
6. Pane according to one of claims 1 through 5, wherein spacers (19) are arranged on the contact surface (8) or the contact surfaces (8', 8").
7. Pane according to one of claims 1 through 6, wherein the connection element (3) contains at least an iron-nickel alloy, an iron-nickel-cobalt alloy, or an iron-chromium alloy.
8. Pane according to claim 7, wherein the connection element (3) contains at least 50 wt.-% to 75 wt.-% iron, 25 wt.-% to 50 wt.-% nickel, 0 wt.-% to 20 wt.-% cobalt, 0 wt.-% to 1.5 wt.-% magnesium, 0 wt.-% to 1 wt.-% silicon, 0 wt.-% to 1 wt.-% carbon, or 0 wt.-% to 1 wt.-% manganese.
9. Pane according to claim 7, wherein the connection element (3) contains at least 50 wt.-% to 89.5 wt.-% iron, 10.5 wt.-% to 20 wt.-% chromium, 0 wt.-% to 1 wt.-% carbon, 0 wt.-% to 5 wt.-% nickel, 0 wt.-% to 2 wt.-% manganese, 0 wt.-% to 2.5 wt.-% molybdenum, or 0 wt.-% to 1 wt.-% titanium.
10. Pane according to one of claims 1 through 9, wherein the solder material (4) contains tin and bismuth, indium, zinc, copper, silver, or compositions thereof.
11. Pane according to claim 10, wherein the proportion of tin in the solder composition (4) is 3 wt.-% to 99.5 wt.-% and the proportion of bismuth, indium, zinc, copper, silver, or compositions thereof is 0.5 wt.-% to 97 wt.-%.
12. Pane according to one of claims 1 through 11, wherein the connection element (3) is coated with nickel, tin, copper, and / or silver, preferably with 0.1 µm to 0.3 µm nickel and / or 3 µm to 20 µm silver.
13. Method for production of a pane with at least one electrical connection element (3) according to one of claims 1 through 12, wherein

    a) solder material (4) is applied on the contact surface (8) or the contact surfaces (8',8") of the connection element (3) as a platelet with a fixed layer thickness, volume, and shape,

    b) an electrically conductive structure (2) is applied to a region of a substrate (1),

    c) the connection element (3) with the solder material (4) is arranged on the electrically conductive structure (2),

    d) energy is introduced at the soldering points (15,15'), and

    e) the connection element (3) is soldered to the electrically conductive structure (2).
14. Use of a pane with at least one electrical connection element according to one of claims 1 through 12, for vehicles with electrically conductive structures, preferably with heating conductors and/or antenna conductors.

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