Pane with electric connection element

Abstract

The present invention relates to a disk (10) with at least one electrical connection element (3), comprising - a flat substrate (1), - an electrically conductive structure (2) which is applied to a surface of the substrate (1), - an electrical connection element (3) which has a crimped region (6) for electrical connection to at least one conductor of a connection cable (5) and a contact region (7) for electrical connection to the electrically conductive structure (2), wherein the connection element (3) is arranged on the electrically conductive structure (2), the crimped region (6) is arranged around the at least one conductor (4) of the connection cable (5), and the contact region (7) is electrically conductively connected to the electrically conductive structure (2), wherein the contact region (7) has at least twice the length of the crimped region (6) in the longitudinal direction of the connection element (3).

Description

[0001] The invention relates to a pane with an electrical connection element, in particular for vehicles.

[0002] In the case of vehicle windows, various methods and arrangements are known for providing windows with an electrical connection element, as these windows are increasingly being equipped with large-area, electrically conductive layers and functional elements that are transparent to visible light. Such windows have electrically conductive structures, which are generally electrically contacted by electrical connection elements with contact surfaces on the window surface. A solder compound forms the electrical connection and simultaneously a mechanical connection between the electrically conductive structure and the connection element.

[0003] Electrical connection elements, particularly for lead-free soldering with electrical structures, are known from WO 2016 / 096248 A1 and WO 2017 / 177653 A1. Mechanical stress on the solder joint is particularly problematic with lead-free solder compounds. Lead-free solders typically exhibit significantly lower ductility than lead-containing solders and are often significantly more brittle. Therefore, lead-free solder compounds are not as capable of withstanding mechanical stress.

[0004] The solder connection between the electrically conductive structure and the connection element may not be able to withstand the mechanical stress properties over time, even due to aging. This leads to undesirable failures in the contacting of the electrically conductive structures. This can result in high repair costs or require the replacement of the pane. WO 2022 / 148667 A1 discloses an electrical connection element having a crimped region, wherein the crimped region is electrically connected to an electrically conductive coating via a solder mass, and has a corrosion-inhibiting coating. In practice, it has been shown that both the solder material and the substrate with the electrically conductive structure can be a weak point under mechanical stress.

[0005] It is desirable to have a pane with an electrical connection element that has a higher pull-off force so that the closure element cannot be detached from the pane even under higher mechanical loads.

[0006] The invention is based on the object of creating a disc with an electrical connection element, with which an increased force must be applied to detach the connection element while being simple and inexpensive.

[0007] The object of the present invention is achieved by a disc with a connecting element according to claim 1. Preferred embodiments are evident from the subclaims.

[0008] The disk according to the invention with at least one electrical connection element comprises a flat substrate, an electrically conductive structure applied to a surface of the substrate, and an electrical connection element having a crimped region for electrical connection to a conductor of a connection cable and a contact region for electrical connection to the electrically conductive structure. Furthermore, the connection element is arranged on the electrically conductive structure, wherein the crimped region is arranged around the conductor of the connection cable and the contact region is electrically conductively connected to the electrically conductive structure. The contact region is longer in the longitudinal direction of the connection element than the crimped region. The contact region has twice the length of the crimped region. This has the advantage that an increased force must be applied to detach the connection element from the disk.Advantageously, this solution is independent of the solder material and substrate used, especially with silver-based electrically conductive structures.

[0009] Preferably, the center of gravity of the connecting element can be arranged within the contact area and outside the crimped area. In particular, the crimped area can be designed such that a point of application of a withdrawal force for detaching the connecting element from the flat substrate is located centrally in the contact area. The advantage lies in the shifting of the center of gravity of the connecting element, so that a force for detaching the connecting element from the disc acts at the center of gravity of the connecting element. This has the advantage that a large force is required to detach the connecting element from the disc.

[0010] In particular, the contact region of the connection element can have a maximum length of 20 mm in the longitudinal direction of the connection element. The contact region can preferably have a length of 6 mm to 15 mm, for example 10 mm or 8 mm. The crimped region can preferably have a length in the longitudinal direction of the connection element in the range of 20% to 50% of the length of the contact region. The contact region of the connection element is preferably connected to the electrically conductive structure via a soldering compound or an electrically conductive adhesive. When the connection cable is subjected to mechanical stress, in particular tension on the connection cable, the connection element creates a very small lever arm, which leads to a high degree of connection stability.

[0011] Furthermore, the crimped area can have a maximum length of 4.5 mm in the longitudinal direction of the connection element. For example, the crimped area can have a length of 4 mm, 3 mm, or 2 mm in the longitudinal direction of the connection element. The total length of the connection element can be suitably selected taking into account the diameter of the connecting cable and is, for example, from 1 mm to 20 mm, preferably from 4 mm to 8 mm, particularly preferably 6 mm, 4.5 mm, or 4.3 mm. This is particularly advantageous with regard to a stable connection between the connection element and the connecting cable.

[0012] The width of the connecting element can be from 1 mm to 5 mm, preferably 2 mm to 3 mm, and particularly preferably 2.5 mm. This is particularly advantageous in terms of the small space required for the connecting element. This also ensures a stable connection between the connecting element and the connecting cable.

[0013] The height of the connecting element can be selected by a specialist, taking into account the diameter of the connecting cable and common standards, and is, for example, from 1 mm to 5 mm or from 2 mm to 3 mm, in particular 2.5 mm. This is particularly advantageous in terms of the small space required for the connecting element and in terms of a stable connection between the connecting element and the connecting cable.

[0014] The connection element has the crimped area around the conductor of the connecting cable. The shape of the crimped area can be arbitrary and can be determined according to the requirements of the individual case by selecting the crimping tool. The crimp shape is determined by the cross-section of the crimped area. The crimped area can be designed, for example, as an oval crimp, polygonal crimp (e.g., square crimp, hexagon crimp, or trapezoidal crimp), O-crimp, or B-crimp.

[0015] In a particularly preferred embodiment, the connection element is designed in the form of a crimp, in particular as a B-crimp.

[0016] With an open crimp, the connecting element is preferably provided as a flat plate or as a pre-bent plate into a crimp claw and is crimped around the connecting cable for crimping. With a closed crimp, the connecting element is preferably designed as a completely closed sleeve (wire end ferrule) and is crimped around the conductor of the connecting cable.

[0017] The connecting cable connects the connecting element and the electrically conductive structure of the substrate to an electrical system such as a control unit or voltage source, which is located outside the wafer.

[0018] The contact area of the connection element is preferably directly connected to the electrically conductive structure via the solder mass or the electrically conductive adhesive. This means a direct mechanical connection between the contact area of the connection element and the electrically conductive structure via the solder mass or the adhesive. This means that the solder mass or the adhesive is arranged between the contact area of the connection element and the electrically conductive structure, thereby permanently and stably fixing the connection element to the electrically conductive structure. In particular, the entire contact area of the connection element is connected to the electrically conductive structure via the solder mass. This means that the solder mass is arranged along almost the entire length of the connection element. This achieves particularly stable adhesion of the connection element to the electrically conductive structure.However, it is also possible for the solder to be arranged only between a section of the connection element and the electrically conductive structure. It is also possible for a special connection surface, such as a bus bar, to be arranged on an electrically conductive coating, and for the connection element to be directly electrically connected to the connection surface.

[0019] According to a further embodiment, the connecting element has a material thickness of 0.1 mm to 2 mm. With such material thicknesses, processing, especially crimping, is particularly easy in the crimped area.

[0020] According to a further embodiment, the connecting element contains a chromium-containing steel with a chromium content of greater than or equal to 10.5 wt.%. Additional alloying components such as molybdenum, manganese, or niobium lead to improved corrosion resistance or modified mechanical properties, such as tensile strength or cold formability. For example, the connecting element can additionally contain admixtures of other elements, including vanadium, aluminum, and nitrogen.

[0021] According to one embodiment of the disc according to the invention with an electrical connection element, the connection element contains at least 66.5 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, 0 wt.% to 2 wt.% niobium and 0 wt.% to 1 wt.% titanium, in particular at least 77 wt.% to 84 wt.% iron, 16 wt.% to 18.5 wt.% chromium, 0 wt.% to 0.1 wt.% carbon, 0 wt.% to 1 wt.% manganese, 0 wt.% to 1 wt.% niobium, 0 wt.% to 1.5 wt.% molybdenum and 0 wt.% to 1 wt.% titanium, or consists of

[0022] The connection element preferably has a coating containing copper, nickel, zinc, tin, silver, gold, or alloys or layers thereof, preferably silver. This improves the wetting of the connection element with the solder compound and improves the adhesion of the connection element. For example, the connection element is coated with nickel, tin, copper, and / or silver. The connection element is provided, in particular, with an adhesion-promoting layer, for example made of nickel and / or copper, and additionally with a solderable layer, in particular made of silver. The connection element is, in particular, coated with 0.1 µm to 0.3 µm of nickel and / or 3 µm to 20 µm of silver. The connection element can be nickel-plated, tin-plated, copper-plated, and / or silver-plated. Nickel and silver improve the current-carrying capacity and corrosion resistance of the connection element, as well as wetting with the solder compound.

[0023] In a preferred embodiment of the invention, the conductor of the connecting cable comprises a plurality of wire strands made of copper. Particularly preferably, the connecting cable comprises at least two, for example, seven or twenty, wire strands.

[0024] In a further preferred embodiment, the crimped region of the connection element and an insulating sheath surrounding the conductor are spaced apart. Preferably, the distance between the crimped region of the connection element and the sheath of the conductor is at least 5 mm, preferably at least 8 mm, in the longitudinal direction of the connection element.

[0025] The sheath of the conductor has no direct contact with the crimped area, so that the conductor is at least partially openly accessible.

[0026] The substrate may contain glass. The substrate may be a glass pane, preferably made of soda-lime glass, as is common for window panes. However, the substrate may also be made of other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or of rigid, clear plastics, such as polycarbonate or polymethyl methacrylate.

[0027] The electrically conductive structure can be formed as an electrically conductive coating, for example, a functional layer. The electrically conductive coating is preferably transparent to visible light. In an advantageous embodiment, the electrically conductive coating is a single layer or a layer structure comprising several individual layers with a total thickness of less than or equal to 2 µm [micrometers], particularly preferably less than or equal to 1 µm. For example, the electrically conductive coating contains at least one metal, preferably silver, nickel, chromium, niobium, tin, titanium, copper, palladium, zinc, gold, cadmium, aluminum, silicon, tungsten, or alloys thereof, and / or at least one metal oxide layer, preferably tin-doped indium oxide (ITO), aluminum-doped zinc oxide (AZO), fluorine-doped tin oxide (FTO, SnO2:F), or antimony-doped tin oxide (ATO, SnO2:Sb).Transparent, electrically conductive layers are known, for example, from DE 20 2008 017 611 U1 and EP 0 847 965 B1. They consist, for example, of a metal layer such as a silver layer or a layer of a silver-containing metal alloy. Transparent, electrically conductive layers preferably have a sheet resistance of 0.1 ohm / square to 200 ohm / square, more preferably from 1 ohm / square to 50 ohm / square, and most preferably from 1 ohm / square to 10 ohm / square.

[0028] The electrically conductive coating can, for example, be an electrically heatable layer that provides the pane with a heating function. Such heatable layers are known per se to those skilled in the art. They typically contain one or more, for example, two, three, or four, electrically conductive layers. These layers preferably contain or consist of at least one metal, for example, silver, gold, copper, nickel, and / or chromium, or a metal alloy, and preferably contain at least 90% by weight of the metal, in particular at least 99.9% by weight of the metal. Such layers exhibit particularly advantageous electrical conductivity while simultaneously providing high transmission in the visible spectral range.The thickness of a single layer is preferably from 5 nm to 50 nm, particularly preferably from 8 nm to 25 nm, whereby advantageously high transmission in the visible spectral range and particularly advantageous electrical conductivity are achieved.

[0029] Furthermore, the electrically conductive structure can contain silver, in particular silver particles and glass frits, and has, for example, a layer thickness of 5 µm to 40 µm.

[0030] The electrically conductive structure is arranged on a surface of the substrate. The electrically conductive structure partially covers the surface of the substrate, but preferably over a large area. The term "large area" means that at least 50%, at least 60%, at least 70%, at least 75%, or 90% of the surface of the substrate is covered by the electrically conductive structure. However, the electrically conductive structure can also extend over smaller portions of the surface of the substrate, for example, if it is a coating within a so-called camera window, a busbar, or a planar antenna.

[0031] The electrically conductive structure can, for example, be a busbar. In the case of the electrically conductive structure in the form of a busbar, the electrically heatable coating is, for example, electrically connected to at least two busbars through which a heating current can be fed into the coating. The busbars are preferably arranged in the edge region of the electrically conductive coating along a lateral edge of the electrically conductive coating. The length of the busbar is typically substantially equal to the length of the lateral edge of the electrically conductive coating, but can also be somewhat longer or shorter. Preferably, two busbars are arranged on the electrically conductive coating, in the edge region along two opposite lateral edges of the electrically conductive coating. The width of the busbar is preferably from 2 mm to 30 mm, particularly preferably from 4 mm to 20 mm.The bus bars are typically each formed in the shape of a strip, with the longer of its dimensions being referred to as the length and the shorter of its dimensions as the width. Bus bars are formed, for example, as a printed and fired conductive structure. The printed bus bar contains at least one metal, preferably silver. The electrical conductivity is preferably achieved via metal particles contained in the bus bar, particularly preferably via silver particles. The metal particles can be located in an organic and / or inorganic matrix such as pastes or inks, preferably as a fired screen printing paste with glass frits. The layer thickness of the printed bus bar is preferably from 5 µm to 40 µm, particularly preferably from 8 µm to 20 µm, and most preferably from 10 µm to 15 µm.

[0032] Alternatively or additionally, the electrically conductive structure can be designed, for example, as an antenna, in particular a surface antenna.

[0033] The soldering compound can be lead-free, which is particularly advantageous with regard to the environmental compatibility of the inventive panel with an electrical connection element. For the purposes of the present invention, "lead-free" means that the soldering compound contains a lead content of less than or equal to 0.1% by weight, in particular no lead at all, i.e., 0% by weight.

[0034] For example, the solder mass contains tin, bismuth, indium, zinc, copper, or silver, in particular compositions thereof. For example, the proportion of bismuth, indium, zinc, copper, silver, or compositions thereof in the solder composition is from 0.5 wt.% to 97 wt.%, in particular from 10 wt.% to 67 wt.%, whereby the proportion of bismuth, indium, zinc, copper, or silver can be 0 wt.%. The solder composition can contain nickel, germanium, aluminum, or phosphorus in a proportion of from 0 wt.% to 5 wt.%. The solder composition contains in particular Bi40Sn57Ag3, Sn40Bi57Ag3, Bi59Sn40Ag1, Bi57Sn42Ag1, In97Ag3, Sn95.5Ag3.8Cu0.7, Bi67In33, Bi33In50Sn17, Sn77.2In20Ag2.8, Sn95Ag4Cu1, Sn99Cu1, Sn96.5Ag3.5, Sn96.5Ag3Cu0.5, Sn97Ag3 or mixtures thereof.

[0035] The layer thickness of the solder mass is preferably less than or equal to 6.0 × 10 -4< m, in particular less than 3.0 × 10 -4< m.

[0036] The solder mass advantageously contains bismuth. It has been shown that a solder mass containing bismuth leads to particularly good adhesion of the connecting element to the substrate, whereby damage to the wafer can be avoided. The proportion of bismuth in the solder mass composition is, for example, from 0.5 wt.% to 97 wt.%, from 10 wt.% to 67 wt.%, or from 33 wt.% to 67 wt.%, in particular from 50 wt.% to 60 wt.% In addition to bismuth, the solder mass contains, in particular, tin and silver or tin, silver and copper. For example, the solder mass contains at least 35 wt.% to 69 wt.% bismuth, 30 wt.% to 50 wt.% tin, 1 wt.% to 10 wt.% silver and 0 wt.% to 5 wt.% copper. In particular, the solder mass contains at least 49 wt% to 60 wt% bismuth, 39 wt% to 42 wt% tin, 1 wt% to 4 wt% silver, and 0 wt% to 3 wt% copper. Furthermore, the solder mass can contain, for example, from 90 wt% to 99.5 wt% tin, or from 95 wt% to 99 wt%.-% tin, in particular from 93 wt.% to 98 wt.% tin. In addition to tin, the solder mass contains, for example, from 0.5 wt.% to 5 wt.% silver and from 0 wt.% to 5 wt.% copper.

[0037] The solder mass emerges from the space between the connection element and the electrically conductive structure with an exit width of less than 1 mm. For example, the maximum exit width is less than 0.5 mm and in particular approximately 0 mm. This is particularly advantageous with regard to the reduction of mechanical stresses in the wafer and the adhesion of the connection element. The maximum exit width is defined as the distance between the outer edges of the connection element and the point of solder mass transfer at which the solder mass falls below a layer thickness of 50 µm. The maximum exit width is measured on the solidified solder mass after the soldering process. A desired maximum exit width is achieved by a suitable selection of solder mass volume and vertical distance between the connection element and the electrically conductive coating, which can be determined through simple tests.The vertical distance between the connection element and the electrically conductive coating can be specified by a corresponding process tool, for example, a tool with an integrated spacer. The maximum exit width can also be negative, i.e., retracted into the space formed by the connection element and the electrically conductive coating. For example, the maximum exit width is retracted in a concave meniscus in the space formed by the connection element and the electrically conductive coating. A concave meniscus is created, for example, by increasing the vertical distance between the spacer and the conductive structure during the soldering process while the solder is still liquid. The advantage lies in the reduction of mechanical stresses in the wafer, particularly in the critical area that occurs when there is a large amount of solder transfer.

[0038] In a further embodiment of the invention, a covering print can be applied at least in one edge region on the surface of the pane facing away from the connecting element.

[0039] The distance of the connecting element to the edge of the pane can be less than 8 cm, preferably less than 5 cm, particularly preferably less than 2 cm.

[0040] One embodiment of the invention comprises a pane arrangement in which a pane according to the invention is an inner pane of a composite pane, wherein the composite pane further comprises an outer pane with an outer surface and an inner surface and at least one intermediate layer which connects the inner surface of the outer pane to an outer surface of the inner pane in a planar manner.

[0041] The inside surface of the laminated pane corresponds to the inside surface of the inner pane and the outside surface of the laminated pane corresponds to the outside surface of the outer pane.

[0042] The outer pane is the pane of the composite pane that, when installed, faces the outside environment, or is intended to do so. The composite pane is typically designed to separate an interior space from the outside environment in an opening (particularly a window opening, for example, a window opening in a vehicle or building). For the purposes of the invention, the inner pane refers to the pane facing the interior space.

[0043] The outer pane and the inner pane each have an outside surface and an inside surface and a circumferential side edge surface running between them.

[0044] In the case of a composite pane, the inner pane and the outer pane are connected to one another by at least one intermediate layer. The intermediate layer is preferably transparent and / or thermoplastic. The thermoplastic intermediate layer is preferably based on polyvinyl butyral (PVB), ethylene-vinyl acetate (EVA), or polyurethane (PU), or on mixtures or copolymers or derivatives thereof, particularly preferably based on PVB. This means that the intermediate layer largely contains the said polymer (a proportion greater than 50% by weight). In addition to the polymer, the intermediate layer may contain further additives, for example, plasticizers, UV absorbers, or stabilizers. Each thermoplastic layer serving as an intermediate layer is preferably formed from at least one thermoplastic film. The thickness of each film is preferably between 0.2 mm and 1 mm. For example, PVB films with standard thicknesses of 0.38 mm or 0.76 mm can be used.The intermediate layer can also comprise multiple layers of thermoplastic material and, for example, be formed from several polymer films arranged one above the other. The outer pane, the inner pane, and the thermoplastic intermediate layer can be clear and colorless, but can also be tinted or colored.

[0045] The outer pane and the inner pane are preferably glass panes, particularly preferably made of soda-lime glass, as is common for window panes. However, one or both of the panes can also be made of other types of glass, such as quartz glass, borosilicate glass, or aluminosilicate glass, or of rigid, clear plastics, such as polycarbonate or polymethyl methacrylate. The thicknesses of the outer pane and the inner pane, independently of one another, are preferably between 0.5 mm and 5 mm, particularly preferably between 1 mm and 3 mm.

[0046] The pane or composite pane can be flat or curved, particularly cylindrical or spherical. The composite pane is particularly preferably used as a windshield or roof pane of a vehicle, particularly a passenger car or truck. The pane or composite pane can have an electrically heated camera window, particularly for camera systems. Camera systems are placed in motor vehicles behind the windshield in the passenger compartment. They thus provide a good view of the vehicle's surroundings and can detect dangerous situations and obstacles in road traffic in a timely manner.

[0047] The outer pane is preferably transparent, particularly for applications where high light transmission is desired. A pane is considered transparent within the meaning of the invention if it has a transmission in the visible spectral range of greater than 70%. However, for panes that are not within the driver's traffic-relevant field of vision, such as roof windows, the transmission can also be much lower, for example, greater than 5%.

[0048] The area of the pane or composite pane can vary widely and can thus be perfectly adapted to the requirements of each individual case. For example, the area of the pane or composite pane can range from 100 cm² to 5 m², preferably from 0.5 m² to 3 m².

[0049] The pane or the composite pane can additionally include the masking print, in particular made of a dark, preferably black, enamel. The masking print is in particular a peripheral, i.e., frame-like, masking print, which is thus arranged in a peripheral edge region. The peripheral masking print primarily serves as UV protection for the assembly adhesive of the composite pane. The masking print can be opaque and full-surface. The masking print can also be semi-transparent, at least in sections, for example, as a dot matrix, striped matrix, or checkered matrix. Alternatively, the masking print can also have a gradient, for example, from an opaque covering to a semi-transparent covering. In the case of the composite pane, the masking print can be applied to the second surface of the outer pane facing the intermediate layer or to the second surface of the inner pane facing away from the intermediate layer.

[0050] It goes without saying that the features and the advantages that can be achieved thereby, which have been described with reference to the pane according to the invention, are applicable or transferable to the composite pane according to the invention and vice versa.

[0051] The various embodiments of the invention can be implemented individually or in any combination. In particular, the features mentioned above and those to be explained below can be used not only in the specified combinations, but also in other combinations or on their own, without departing from the scope of the present invention.

[0052] A further aspect of the invention encompasses the use of the pane or pane arrangement according to the invention as a vehicle pane in means of transport for land, air, or water traffic, in particular in motor vehicles, and in particular as a windshield, for example, a windshield. The pane according to the invention is designed, in particular, as a heatable pane or as a pane with an antenna function.

[0053] The invention is explained in more detail below with reference to figures and exemplary embodiments. The figures are schematic representations and not to scale. The figures do not limit the invention in any way. They show:

[0054] Figure 1 shows a side view of an electrical connection element with a crimped area according to an embodiment not according to the invention, Figure 2 shows a side view of a disc according to the invention with an electrical connection element, Figure 3 shows a side view of the disc according to the invention with the electrical connection element, Figure 4 shows a perspective view of the electrical connection element designed as a B-crimp, and Figure 5 shows a cross section BB' through the disc 1 with connection element according to Figure 4 .

[0055] Figure 1shows an electrical connection element 3' with a crimped area 6'. The connection element 3' is crimped along its entire length around the end area of a connecting cable 5'. The connecting cable 5' contains an electrically conductive core, which is designed as a conventional stranded wire conductor. The connection element 3' is thus designed as a crimp. The length of the stripped area exceeds the length L of the crimp by, for example, 0.5 mm to 1 mm to ensure the flexibility of the connecting cable 5'.

[0056] The electrical connection element 3' has a contact area 7'. The contact area 7' is electrically and mechanically connected to an electrically conductive structure 2' applied to a substrate 1' via a solder compound 8'.

[0057] If the connecting cable 5' is pulled perpendicular to the substrate 1' with a pulling force F1, the connecting element 3' detaches from the substrate 1'. F1 is the pulling force required to release the mechanical connection between the substrate 1' and the connecting element 3'. The required pulling force F1 is also referred to as the pull-off force. The required pulling force F1 is, for example, 50 Newtons.

[0058] Figure 2 shows a side view of a pane 10 according to the invention with an electrical connection element 3. The pane comprises a substrate 1. The substrate 1 is, for example, a 3 mm thick thermally toughened single-pane safety glass made of soda-lime glass. The substrate 1 has, for example, a width of 150 cm and a height of 80 cm.

[0059] An electrically conductive structure 2 is applied to the substrate 1. The electrically conductive structure 1 can be formed as an electrically conductive coating, for example a functional layer, or as a special connection surface, for example a busbar, arranged on the electrically conductive coating. The electrically conductive structure 2 can, for example, be an electrically heatable coating that provides the pane with a heating function. However, the electrically conductive structure 2 can also extend over smaller portions of the surface of the substrate 1, for example if it is a coating within a so-called camera window or a busbar that contacts the coating of the camera window.

[0060] The connection element 3 is then electrically connected to the connection surface via a solder paste 8. The electrically conductive structure 2 contains silver particles and glass frits. In the edge region of the wafer, the busbar can be widened to a width of 10 mm as the electrically conductive structure 2, thus forming a contact surface for the electrical connection element 3.

[0061] The connecting element 3 is crimped along the crimped region 6 around the end region of a connecting cable 5. The connecting element 3 can be formed in one piece, wherein the longer of its dimensions is referred to as the length and the shorter of its dimensions is referred to as the width B.

[0062] The connection element 3 has the crimped region 6 and a contact region 7. The contact region 7 has at least twice the length of the crimped region 6 in the longitudinal direction of the connection element 3. Furthermore, the contact region 7 can have a maximum length of 20 mm. For example, the contact region can have a length L of 15 mm, 10 mm, 8 mm, or 6 mm in the longitudinal direction of the connection element 3. The length of the connection element can be suitably selected taking into account the diameter of the connecting cable 5. For example, the length of the connection element can be from 1 mm to 20 mm, preferably from 4 mm to 10 mm, particularly preferably 9 mm, 8 mm, 6 mm, 4.5 mm, or 4.3 mm.

[0063] In the contact area 7 between the electrical connection element 3 and the electrically conductive structure 2, the solder mass 8 is applied, which creates a permanent electrical and mechanical connection between the electrical connection element 3 and the electrically conductive structure 2.

[0064] Solder mass 8 is lead-free and contains, for example, 96.5 wt% tin, 0.5 wt% copper, and 3 wt% silver. Alternatively, solder mass 8 can contain, for example, 30% In, 65% Sn, 4% Ag, and 1% Cu. Solder mass 8 has a thickness of, for example, 250 µm.

[0065] The crimped region 6 preferably has a length in the longitudinal direction of the connection element 3 in the range of 20% to 50% of the length of the contact region. The crimped region 6 of the connection element 3 can have a maximum length of 4.5 mm in the longitudinal direction of the connection element 3. The crimped region 6 can have a length of 4 mm, 3 mm, or 2 mm in the longitudinal direction of the connection element 3, for example. The crimped region 6 can be designed such that a point of application of a withdrawal force for detaching the connection element 3 from the flat substrate is arranged centrally in the contact region 7, wherein the withdrawal force acts perpendicular to the substrate 1 ( Figure 3 ).

[0066] The connecting cable 5 contains an electrically conductive conductor, also called a core, which is designed as a conventional stranded wire conductor. The connecting cable 5 can have a cross-sectional area of 0.1 mm 2 to 8 mm 2 , for example 0.35 mm 2 or 0.75 mm 2 . The cross-sectional area can be circular or round. The connecting cable 5 further contains a polymeric insulating sheath, which is removed in the end region to enable electrical contact between the electrically conductive conductor of the connecting cable 5 and the connecting element 3. The length of the stripped region exceeds the length of the crimped region 6 by, for example, 5 mm to 8 mm, to ensure the bendability of the connecting cable 5. The connecting cable 5 can be designed to be flexible.

[0067] During the manufacture of the disc, the connecting element 3 was provided as a small plate with a material thickness of, for example, 2 mm, 1 mm, 0.8 mm, 0.4 mm or 0.1 mm, which was bent around the connecting cable 5 using a crimping tool and permanently and securely connected to the connecting cable 5 by crimping. The length of the contact area 7 corresponds to twice the length of the crimped area of the connecting element 3. The total length of the connecting element 3 is, for example, approximately 9 mm. The width B of the connecting element 3 (crimp width b) is, for example, approximately 5 mm, 2.5 mm or 2 mm. The height H of the connecting element can be suitably selected by a person skilled in the art, taking into account the diameter of the connecting cable and common standards, and is, for example, from 1 mm to 5 mm or from 2 mm to 3 mm, in particular 2.5 mm. The connecting element 3 contains a chromium-containing steel with a chromium content of greater than or equal to 10.5 wt.%.Furthermore, the connecting element 3 can have a coating containing copper, nickel, zinc, tin, silver, gold, or alloys or layers thereof, preferably silver. This results in improved wetting of the connecting element 3 with the solder mass 8 and improved adhesion of the connecting element.

[0068] The distance of the connecting element 3 to a pane edge 9 can be less than 8 cm, preferably less than 5 cm, particularly preferably less than 2 cm.

[0069] Figure 3 shows a side view of a pane 10 according to the invention with an electrical connection element 3 from Figure 2 If the connecting cable 5 is pulled perpendicular to the substrate 1 with a force F2, the connecting element 3 detaches from the substrate 1. F2 is the pulling force required to release the mechanical connection between the substrate 1 and the connecting element 3.

[0070] Surprisingly, it has been shown that such a disc 1 according to the invention with connecting element 3 has a significantly higher necessary pulling force than the disc 1' according to Figure 1 The required pulling force is F2 > F1. The required pulling force F2 corresponds to the peel force. The peel force must be applied perpendicular to the substrate to detach the connecting element 3 from the flat substrate 1.

[0071] Figure 4 shows a perspective view of the electrical connection element 3 designed as a B-crimp with the connection cable 5.

[0072] Figure 5 shows a cross section BB' through the connecting element 3 according to Figure 4with the substrate 1. The connecting element 3 has the shape of a B-crimp. The lateral edges of the connecting element 3 are bent around the connecting cable 5 and, by piercing the crimping tool, are sunk into the electrically conductive core of the connecting cable 5, whereby the wire strands of the connecting cable 5 extend evenly on both sides into the contact interior. The characteristic crimp shape shows two rounded coatings in profile, similar to the letter "B." The characteristic crimp shape is arranged on the upper side of the connecting element 3 facing away from the substrate 1. The contact area 7 of the connecting element 3 is arranged opposite the characteristic crimp shape, i.e., on the crimp base. This ensures advantageous wetting of the connecting element 3 with the solder compound 8.

[0073] By means of a connecting element 3 according to Figure 2The disc 1 can be provided with an increased pull-off force, thus achieving a stable bond between the connecting element and the substrate. The degree of mechanical strength can be adjusted depending on the requirements of the individual case by designing the crimped area and the contact area. List of reference symbols:

[0074] 1Substrate 2Electrically conductive structure 3Connection element 4Connection cable conductor 5Connection cable 6Crimped area 7Contact area 8Solder mass 9Disk edge 10Disk 11Edge area LLength of the contact area 7 BWidth of the connection element

Claims

1. A disc (10) with at least one electrical connection element (3), comprising • a flat substrate (1), • an electrically conductive structure (2) which is applied to a surface of the substrate (1), • an electrical connection element (3) which has a crimped region (6) for electrical connection to at least one conductor of a connection cable (5) and a contact region for electrical connection to the electrically conductive structure (2), wherein the connection element (3) is arranged on the electrically conductive structure (2), the crimped region (6) is arranged around the at least one conductor (4) of the connection cable (5) and the contact region (7) is electrically connected to the electrically conductive structure (2), wherein the contact region (7) has at least twice the length of the crimped region (6) in the longitudinal direction of the connection element (3).

2. Disc (10) according to claim 1, wherein the crimped region (6) is designed such that a point of application of a withdrawal force (F2) for detaching the connection element (3) from the flat substrate (1) is arranged centrally in the contact region (7).

3. Disc (10) according to claim 1 or 2, wherein the contact region (7) has a maximum length (L) of 20 mm, preferably 15 mm, particularly preferably 10 mm in the longitudinal direction of the connecting element (3).

4. Composite disc (10) according to one of claims 1 to 3, wherein the crimped region (6) has a length in the longitudinal direction of the connection element (3) in the range of 20% to 50% of the length (L) of the contact region (7).

5. Disc (10) according to one of claims 1 to 4, wherein the connecting element (3) has a width (B) of 1 mm to 5 mm, preferably 2 mm to 3 mm, particularly preferably 2.5 mm.

6. Disc (10) according to one of claims 1 to 5, wherein the connecting element (3) has a material thickness of 0.1 mm to 2 mm.

7. Disc (10) according to one of claims 1 to 6, wherein the connecting element (3) is designed in the form of a crimp, in particular as a B-crimp.

8. Disc (10) according to one of claims 1 to 7, wherein the connecting element (3) contains a chromium-containing steel with a chromium content of greater than or equal to 10.5 wt.%.

9. Disc (10) according to one of claims 1 to 8, wherein the connecting element (3) has a coating containing copper, nickel, zinc, tin, silver, gold or alloys or layers thereof, preferably silver.

10. Disc (10) according to one of claims 1 to 9, wherein the conductor (4) of the connecting cable (5) has a plurality of wire strands formed from copper.

11. Disc (10) according to one of claims 1 to 10, wherein the crimped region (6) of the connection element (3) and an insulating sheath surrounding the conductor (4) are spaced apart, preferably with a distance of at least 5 mm in the longitudinal direction of the connection element (3).

12. Disc (10) according to one of claims 1 to 11, wherein the electrically conductive structure (2) contains silver.

13. Pane (10) according to one of claims 1 to 12, wherein the distance of the connecting element (3) to the pane edge (9) is less than 8 cm, preferably less than 5 cm, particularly preferably less than 2 cm.

14. Disc (10) according to one of claims 1 to 14, wherein the center of gravity of the connecting element (3) is arranged within the contact area (7) and outside the crimped area (6).

15. Pane arrangement in which a pane (10) according to one of claims 1 to 14 is an inner pane (1) of a composite pane, the composite pane further comprising - an outer pane (2) with an outer surface (I) and an inner surface (II) and - at least one intermediate layer (3) which connects the inner surface (II) of the outer pane (2) to an outer surface (III) of the inner pane (1) in a planar manner.

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