EP1619759B1 - Electrical connection with cross-section transition, procedure and manufacturing and laminated glass with such connection - Google Patents

Abstract

Electrical conducting connection comprises an insulating and sealing composition (14) and a protective body (10) arranged temporarily after applying the insulating composition so that it completely surrounds it with common boundary surfaces. Independent claims are also included for the following: (1) Process for the production of an electrical conducting connection; and (2) Composite disk having an outer connection formed by the above electrical conducting connection.

Description

The invention also relates to a method for producing such a line connection and to a composite pane with electrical components and at least one such line connection.

Known are such line connections, which include a transition from a ribbon cable to a cable, of various applications in composite disks, in the composite (at least two rigid disks and a surface-adhesive bonding adhesive film or layer) electrical components are installed. The latter may be, for example, heating wires or layers and their bus bars, antenna elements, solar cells or other flat-building elements. Correspondingly equipped composite discs can be found in automobiles (windscreen, rear and side windows, there usually with heating and / or antenna elements) and also in the construction sector.

In order to lead out a flexible line connection as an external connection from the interior of the composite, without having to pierce one of the connected panes, flat cables are usually used, which consist of at least one thin carrier foil (for example of polyimide or PEN) and at least one metallic conductor track (cf. 195 36 131 C1, DE 102 49 992 C1). In most cases, another cover sheet is provided, so that the flat conductor forms a total of a three-layer laminate. Overall, this is still sufficiently thin to be placed in a composite (the thickness of the intermediate or adhesive layer is 0.76 mm, the total thickness of the flat conductors of interest here is 0.2 mm).

Most of these flexible flat conductors are soldered to pads that are close to the edge of the composite disc inside the composite. They then extend outward beyond this edge and are connected at a short distance from said edge with a normal (round) cable. The conductor (s) of the cable assembled by the meter are contacted with the strip conductor (s) of the flat conductor, usually by soft soldering. In the area of the solder joints, of course, at least one cover film of the flat conductor is removed in order to expose the printed conductor (s). In the area of Cross-sectional transition from the flat conductor to the cable has so far been the conductor (s) completely exposed or executed exposed.

In order to mechanically protect this cross-sectional transition after soldering and to electrically insulate it to the outside, it is encased or encapsulated with the aid of a plastic compound, whereby a shallow casting block (protection body) is formed, but which is still slightly wider than the flat conductor. The protective body completely encloses the cable-facing end of the flat conductor. In the known solutions, the protective body made of polyamide, a relatively hard compared with the flexible electrical conductors material. This is available in transparent or colored version. The hitherto conventional protective body are usually colored black. They also have no recesses in the connection area, so that no visual inspection of the connection point is possible. The importance of such visual inspections is discussed in the already mentioned DE 102 49 992 C1 in connection with the electrical contacting in composite disks.

DE 41 36 901 A1 describes an example of a solder joint with an insulating molded protective body.

EP 1 058 349 A1 and US Pat. No. 5,724,730 show solder joints between flat conductor or flexible conductor cables and wire cables which are each enveloped by insulating protective bodies. In both latter documents also forms for producing the potting or protective body are shown, which do not remain at the compounds.

Said EP 1 058 349 A1 shows an embodiment in which a fixed housing surrounds the actual connection point and is itself completely enveloped by a potting compound. The lines can still be wrapped within the protective body with separate sealing strip. The aforementioned US Patent 5,724,730 shows an embodiment in which the flat conductor is at the exit from the protective body surrounded by a separately prefabricated and attached elastic kink protection, which is partially potted with the protective body.

It is not possible in a mass production with reasonable effort to combine a uniform protection body made of relatively strong material with sufficient adhesion with the polyimide carrier and cover films of the flat conductor. This has certain disadvantages for the preferred application described here because composite disks are increasingly being installed, especially in automobiles, even with exposed edges. The connections with flat conductors of the embodiment discussed here are often in the lower edge region These discs and are continued within the (usually metallic) body to the vehicle electrical system.

Depending on the installation situation, this can lead to a fairly strong effect of running or aufwassendem water on the area of the cross-sectional transition from flat conductor to cable. The risk of short circuits (creepage distances) to the body is not completely ruled out with the known solution with a solder joint between the flat conductor and cable relatively hard protective body, since fine gaps can form between the films of the flat conductor and the protective body.

The risk is exacerbated by mechanical effects that can not be ruled out during the manufacture, transport and installation of such composite discs and can lead to damage to the films in the cross-sectional transition. Friction or kinking on relatively sharp and stiff edges of the potting block or protective body can damage the films and expose the flat conductors locally.

As a further functional boundary condition is added that the prefabricated and equipped with the terminals composite discs nor the usual bonding process, ie the action of heat and pressure z. B. in an autoclave, must be subjected, therefore, the line connections must withstand. Thus, the materials used must be able to withstand temperatures up to about 150 ° C harmless.

DE 195 10 341 A1 describes a method for strain-relieved fixing of an electrical line in a plug housing. The multi-pole possibly made of round cables line is first electrically connected by soldering with contact elements such as pins or with a continuing ribbon cable. The connection area is then inserted into a housing. Then, the end of the lead is embedded in the housing by means of a compound adhering to the insulating material of the lead (eg, a hot melt adhesive). The latter is solid at room temperature and causes a strain relief of the line or the solder joint.

The invention is based on the object to further improve a line connection of the aforementioned type with respect to the preferred use as a connection element for composite disks with electrical components. It is also intended to provide a method of making such a line connection.

This object is achieved with regard to the line connection according to the invention with the features of claim 1. The features of claim 12 indicate a corresponding manufacturing process, while claim 16 relates to a with at least relates to such a compound compound equipped compound disc. The features of each of the independent claims subordinate claims indicate advantageous developments of this invention.

After lengthy tests with the material of the protective body, which itself is available in different hardnesses, it was found that by modifying the shape and material of the protective body alone no compromise between a sufficient mechanical strength as the main task and a satisfactory even in weathering electrical insulation Junction could be found. The problem of adhesion to the carrier and cover films could not be satisfactorily solved.

Finally, it was decided to surround the actual electrical (solder) connection with a softer insulating and sealing compound instead of the protective body. Here, too, problems were still encountered in the selection of the insulating material, in particular with regard to its upper temperature limit. However, it was finally possible to find adhesives with adequate adhesion to metals and polyimide films, which also endure the autoclave temperatures (up to 150 ° C.) without damage, ie in particular without reducing their adhesion, their insulating properties and their elasticity. They also endure a final process of overmolding with the material of a protective body. As an adhesive or potting material come polyamide (thermoplastic hot melt adhesive), acrylate and epoxy resin systems, possibly also silicone in question.

Furthermore, it was found that a minimization of the area surrounding the insulating and sealing compound in the connection area brought further advantages, which did not have to be considered before, because the protective body, as mentioned, completely encloses the entire flat conductor anyway. Specifically, you must in the field of electrical connection, a relatively wide trace does not expose the full width, but it is sufficient if you take the cover or carrier film on a slightly the thickness of the cable width exceeds width.

In itself, only this relatively small area in relation to the overall width of the flat conductor still has to be covered or even enveloped by the permanently elastic insulating compound. When moving in this area, then too no major deformations and moments occur within the insulating, so that their mechanical stress can be kept quite low. Basically, the mass can be applied externally unshaped. In terms of a defined material usage, however, it is preferably attached with a geometrically simple, reproducible shape.

After applying this preferably transparent insulating in a first stage of the process, which is preferably done immediately after the manufacture of the solder joint, on the one hand an excellent seal against the ingress of liquid and / or moisture is created, which practically excludes the occurrence of short circuits and corrosion damage. On the other hand, the protected solder joint can still be visually inspected.

Nevertheless, because of the considerable mechanical and thermal stresses during further processing (bonding process, transport, installation in vehicle body) and in the installation environment, it is not possible to dispense with the protective body, since the insulating compound alone is not or only slightly mechanically and thermally loadable.

As before, this protective body can be produced in a second stage of the process simply by molding or encapsulation of the connection region and the previously applied insulating compound with a suitable plastic compound. Thus, the insulating material is fully embedded in the final state within the protective body, so that the risk of leakage is minimized as far as possible with reasonable effort. The outer contour of the insulating material thus forms a common body or interface with the protective body. In particular, the outer shape of the insulating compound can be reduced in size to emulate the outer shape of the protective body.

Another significant improvement of the protective body consists in a "softening" of its edge facing the flat conductor in order to minimize the forces acting on the flat conductor or on its foils as far as possible. One can simply try to achieve this by reducing the cross-section in the form of a ramp. Another, preferably with the above-mentioned combinable solution is to provide the edges of a softer material, which can be sprayed by a two-component injection molding or can be applied as a separate component. It is also advantageous if the edge of the protective body pointing toward the flat conductor-seen in the plan view of the flat conductor-has a rounding, since this avoids a straight bending edge. This rounding can also be provided when molding the insulating.

The protective body itself can be further modified, for example by one or more recesses, which now also allow a visual inspection of the joint. Further recesses or lugs can also serve as mounting or fastening elements, for example for latching the protective body on corresponding projections in the body or on the frame of the composite pane.

If optical control of the solder joint is desired, then of course the transparent insulating compound must be combined with a likewise optically transparent protective body, if one does not want to provide it with a recess as a viewing window.

Such electrical line connections are preferably used for producing external electrical contacts for electrical components such as heating wires or layers and their bus bars, for antenna elements, for photovoltaic solar cells and the like, which are installed between rigid glass and / or plastic panes of composite panes. It may be necessary and useful to provide a separate line connection for each pole. If necessary, of course, each line connection comprise a plurality of parallel lines, which are then all to connect in the region of the cross-sectional transition between the flat conductor and cable and to be wrapped with the insulating compound and the protective body. In the case of a pure (monopolar) antenna function with ground or reference potential on a metallic body, a composite pane can also be equipped with only one single-pole connection device of the type described here. In any case, the composite disc forms a unitary object with its conduit connections, since the conduit connections can not be separated from the composite disc without loss of function.

Further details and advantages of the subject of the invention will become apparent from the drawing of an embodiment and its subsequent detailed description below.

Fig. 1

eine Ansicht einer Leitungsverbindung mit einem Querschnittsübergang und einem diesen abdeckenden Schutzkörper,

Fig. 2

einen Schnitt durch den Bereich des Querschnittsübergangs zum Verdeutlichen der verbesserten Isolierung mittels der erfindungsgemäß innerhalb des Schutzkörpers vorgesehenen oder darin eingebetteten Isoliermasse,

Fig. 3

einen Schnitt wie in Fig. 2 mit einer definiert geformten Isoliermasse.

It show in a simplified, not to scale representation

Fig. 1

a view of a line connection with a cross-sectional transition and this covering protective body,

Fig. 2

a section through the region of the cross-sectional transition to illustrate the improved insulation by means of inventively provided within the protective body or embedded therein insulating material,

Fig. 3

a section as in Fig. 2 with a defined shaped insulating.

According to FIG. 1 , the line connection 1 consists of a cable 2 and a flat conductor 4, which in this case should be designed in a simplified manner with only a single electrical conductor (which, of course, does not preclude a multi-pole design). A conductor 5 of the flat conductor 4 is indicated by dashed lines. A metallic soul 3 of the Cable 2 is stripped at its end connected to the flat conductor 4 end and soldered to the conductor 5.

This solder joint lies on an exposed region of the conductor track 5, which is surrounded by a cutting edge 8. The exposed electrically conductive and to be insulated area is significantly narrower than the entire conductor 5 in order to keep it as small as possible. Of course, it still has to offer sufficient space for the laying and soldering of the cable end, whereby one usually sets at most twice the width of the cable. Of course, less space may also be required on a case-by-case basis if the quantity of solder can be dimensioned with sufficient accuracy.

In the thus formed cross-sectional transition between the cable 2 and the flat conductor 4 is a protective body 10 made of a mechanically durable and electrically insulating plastic, for. As polyamide arranged. Preferably (but not necessarily, as will be explained later), said cross-sectional transition with this protective body 10 is completely encapsulated. The latter is additionally provided with a viewing window 11, which allows optical control of the solder joint between the cable end 3 and the conductor track 5. Alternatively, the protective body can also be made entirely or partially of a transparent material.

The protective body 10 has here at its points away from the flat conductor corners on both sides of the cable 2 eyelets as fasteners 12, with which it can be set in an installation environment, for example in a vehicle body. Furthermore, it has a flat conductor 4 (seen in plan view of the flat conductor 4) rounded and resilient end portion 13. Thus, the risk of damage to the lead is minimized by kinking and chafing at the edge of the protective body. On the end portion 13 will be discussed in more detail. With a dot-dashed oval the area is indicated, which is covered by an insulating material 14. This is at least the solder joint and the entire section 8; However, the extent can also be greater, as will be discussed with reference to FIG. 3.

With a dotted line V, the edge of a composite disk is indicated, over which the flat conductor 4 extends in the fully assembled state, wherein the protective body 10 is outside the composite. Within the space between two individual slices of the composite of the flat conductor 4 is electrically connected in a known and therefore not shown manner with an electrical component. In general, leaving a distance of only a few millimeters between this disc edge and the protective body 10. The composite connection points or surfaces for soldering of the flat conductor or its conductor (s) are usually very close to the said edge of the composite disc, so that the flat conductor 10 must be a total of only a few inches long. The edge region of the composite pane, in which the flat conductor is inserted and in which it is electrically contacted, is usually optically laminated by an opaque color layer.

FIG. 2 shows better the internal structure of both the flat conductor 4, which, in addition to the conductor track 5, also comprises a carrier foil 6 and a cover foil 7, as well as the lamination of the connection point or transition region. The cover film 7 above the conductor track 5 ends in the cut edge 8, which surrounds the connection region (see Fig. 1). It should be noted that the individual layers of the flat conductor sections are usually made up separately, that is already provided with the required lengths and contours and cutouts, and then laminated using thin adhesive layers. It also recognizes again the protective body 10 and the recess 11th

A metered amount of a soft solder 9 ensures the electrical and mechanical connection between the core 3 of the cable 2 and the conductor 5. It can be seen here well that the end or the soul 3 of the cable 2 rests on the conductor 5. The solder 9 is not indicated in detail in Fig. 1 for simplicity, and it is understood that the cable end is deviating from the highly simplified representation also completely tin-plated.

In the transition in Fig. 1 only indicated as oval, temporally mounted in front of the protective body transparent insulating 14 covers the entire area of the solder joint, in particular all exposed metallic surfaces, and also covers the cutting edge 8. It does not obstruct the view of the solder joint , The task of the insulating compound 14 is to ensure by adhesion to the surrounding components, ie to the metallic connecting elements 3 and 5, to the solder 9 and to the films 6 and 7 that no moisture penetrates into this area. It can be dispensed with a complete wrapping of the end portion of the flat conductor 4 with the insulating 14, if it adheres sufficiently secure to the films.

The insulating compound 14 has common body edges with the molded around them protective body 10, since the latter is sprayed after the attachment (and possibly setting) of the insulating compound. The outlined irregular outlines of the insulating 14 here in a series production of a defined contour (see Fig. 3) soft, which one by specifying a volume of insulating material 12 on the one hand and plastic mass for the protective body on the other hand is reproducible and set with predetermined shapes.

In any case, the attachment of the insulating material is a separate process step, after its implementation after the production of the solder joint between the cable core 3 and the conductor 5 is already created a watertight connection.

Notwithstanding the illustration in Fig. 2, it may also be sufficient to spray the protective body 10 on the flat conductor 4 only on one side or on one side with gripping the edges of the flat conductor 4, if its material adheres sufficiently firmly to the film and the insulating. It then forms only one-sided coverage of the cross-sectional transition.

In the cross section of Fig. 2 it can be seen also that the protective body 10 in its already mentioned end portion 13 on both sides of the flat conductor 4 in the form of ramps 15 has tapered cross-sections, which comparatively a gradual transition from that in relation to the flat conductor and the cable form stiff volume of the protective body to the flexible flat conductor. Thus, together with the visible in Fig. 1 rounding of this edge across the width of the flat conductor 4 a good protection against damage to the flat conductor is ensured under mechanical stress.

Simplified, the protective body is shown here in one piece and homogeneously with the end region. You can make the latter of the same material as the protective body itself. If required, it is made of a softer material. This can be sprayed by two-component spraying later (or in a suitable turning device) to the pre-sprayed protective body and the flat conductor, or you can use prefabricated moldings for the end, in a suitable manner with the protective body 10 and possibly with the flat conductor 4 connect.

Finally, FIG. 3 shows a series near execution in cross section. The insulating and sealing compound 14 is here formed with an outline defined by a mold, but this mold is not the protective body and is removed before its production. Also in the embodiment of Fig. 2, the insulating and sealing compound is applied independently of and in time before the later molded protective body 10.

In Fig. 3 it can be seen that the outer contour of the insulating material 14 is substantially similar to the outer contour of the (here only dashed lines) protective body, and in particular also has a to the exit of the flat conductor 4 towards tapered ramp shape. The protective body 10 can then be made relatively thin-walled, so that the insulating material 14 has a certain buffer volume for absorbing mechanical bending loads of the electrical conductors.

It should be remembered that this principled representation can not accurately reflect the true thickness ratios. The thickness of the protective body 10 will be only a few millimeters in reality.

Claims (16)

1. Electrical line connection (1) with a cross-sectional transition from a flat conductor (4), comprising a substrate film (6) and at least one conductor track (5), to a cable (2), wherein at least one electrical connection is provided between the at least one conductor track and the cable at said cross-sectional transition, said electrical connection being covered with an adhering electrically insulating compound, and wherein the cross-sectional transition and the electrical connection are covered by an additional, relatively rigid protective body (10) in addition to the adhering compound, characterised in that the adhering insulating and sealing compound (14) is permanently elastic and in that the protective body (10) is applied after the application of the insulating compound (14) in such a way that it completely surrounds the latter with common boundary surfaces.
2. Line connection according to claim 1, characterised in that the insulating and sealing compound (14) is applied with a defined body shape by means of a forming tool that is independent of the protective body (10).
3. Line connection according to claim 1 or 2, characterised in that the protective body (10) is injection-moulded from a plastics material onto one or both flat sides of the flat conductor (4).
4. Line connection according to one of the preceding claims, characterised in that at least an end region (13) of the protective body (10) which points towards the flat conductor (4) is designed to be mechanically flexible.
5. Line connection according to claim 4, characterised in that the protective body (10), in the end region (13), has at least one ramp (15) which slopes down towards its edge pointing towards the flat conductor (4).
6. Line connection according to one of claims 4 or 5, characterised in that the end region (13) is made of a softer material than the protective body (10) itself.
7. Line connection according to one of the preceding claims 4 to 6, characterised in that the end region (13) has a rounding towards the flat conductor (4).
8. Line connection according to one of the preceding claims, the flat conductor (4) of which furthermore comprises a cover film (7) that covers its conductor track (5), characterised in that the cover film, in the region of each electrical connection to the cable, has a cut edge (8) to form a cut-out which is not wider than twice the width of the connecting surface between the respective conductor track (5) and the cable (2).
9. Line connection according to one of the preceding claims, characterised in that the protective body (10) has at least one opening (11) for visual inspection of the connecting area, and the insulating compound consists of an optically transparent plastic.
10. Line connection according to one of the preceding claims, characterised in that the insulating compound (14) consists of a polyamide, an acrylate adhesive, an epoxy adhesive, or of a silicone.
11. Line connection according to one of the preceding claims, characterised in that the protective body (10) comprises at least one fixing element (12) for fixing it in an installation environment.
12. Method for producing an electrical line connection (1) with a cross-sectional transition from a flat conductor (4), comprising a substrate film (6) and at least one conductor track (5), to a cable (2, 3), wherein at least one electrical connection is produced between the at least one conductor track (5) and the cable (2, 3) at said cross-sectional transition, characterised by the steps:

    - completely covering the electrical connection with an adhering, permanently elastic and electrically insulating compound (14),

    - moulding-on an additional, relatively mechanically rigid protective body (10) which covers the cross-sectional transition and the electrical connection in addition to the adhering compound (14).
13. Method according to claim 12, characterised in that the electrically insulating compound (14) is applied by means of a forming tool that is independent of the protective body (10).
14. Method according to claim 12 or 13, characterised in that the electrically insulating compound (14) is applied in such a way that it covers both flat sides of the flat conductor (4).
15. Method according to claim 12 or 13 or 14, characterised in that the protective body (10) is applied by injecting it around the insulating compound (14).
16. Composite disc comprising at least two rigid, transparent discs made of glass and/or plastic and an adhesive layer or adhesive film which adhesively bonds these two discs together over their entire surface, and also comprising at least one electrical component with an outer connection which comprises a flat conductor (4) extending beyond the outer edge (V) of the composite disc and having a section embedded between the two discs in the adhesive layer, characterised in that the outer connection is formed by a line connection (1) designed or produced according to one of the preceding claims, the protective body (10) of which is located outside the composite disc.

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