Method for producing three-dimensionally shaped heating film, heating film, cover plate for headlamp

Abstract

The invention relates to a method for producing a three-dimensionally shaped heating film (18), comprising the following steps: providing a substrate (20) which extends along a film plane (22) and which has a first substrate region (24) for receiving a heating wire (36) and a second substrate region (26) adjacent to the first substrate region (24), at least one contact site (38) can be or is arranged in the second substrate region (26); arranging at least one connector pad (34) on the substrate (20) in the first substrate region (24); arranging at least one heating wire (36) on the substrate (20) in the first substrate region (24); connecting the at least one connector pad (34) and the at least one heating wire (36); shaping the second substrate region (26) to form a three-dimensional shape deviating from the film plane (22); and arranging at least one additional pad (40) on the substrate (20) in the first substrate region (24) and in the second substrate region (26) in order to connect the at least one contact site (38) and the at least one connector pad (34).

Description

Technical Field

[0001] The invention relates to a method for producing a three-dimensionally shaped heating film, a heating film and a cover plate. Background Art

[0002] DE 10 2016 111 493 A1 discloses a method for producing a printed circuit provided with a thermoformed film, wherein conductive tracks are formed in a serpentine or zigzag shape in a thermoformed middle section.

[0003] Due to the elongation of the film and the conductive traces, wrinkle formation and complete tearing of the traces can occur during thermal deformation, rendering the traces poorly or non-conductive. Summary of the invention

[0004] Sensors for driver assistance systems, such as radar or lidar, are integrated, for example, in headlights. The headlights have a cover plate, which must transmit the sensor signal at least once. For this purpose, it is required that a defined wavelength can penetrate the cover plate in order to generate reliable sensor data. For example, water ice and dew are critical for the above-mentioned sensor types. The sensor signal can be reliably ensured by the cover plate, for example also by heating in the cover plate.

[0005] The cover plate has a firm bend and / or a firm stop relative to the engine hood and / or the bumper. Therefore, the components arranged on or in the cover plate must also realize these bends and stops.

[0006] The invention is therefore based on the object of providing a method for producing a three-dimensionally shaped heating film, in which components arranged on the heating film are not damaged.

[0007] The object on which the present invention is based is achieved by a method having the characteristics of the present invention. The method comprises the following steps, preferably carried out in the specified order: - providing a substrate extending along the membrane plane, the substrate having a first substrate region for receiving the heating wire and a second substrate region adjacent to the first substrate region, wherein at least one contact site can be or is arranged in the second substrate region; - arranging at least one connector pad on the substrate in the first substrate region; - arranging at least one heating wire on the substrate in a first substrate region; - connecting at least one connector pad and at least one heating wire; - shaping the second substrate region to form a three-dimensional shape that deviates from the plane of the film; and At least one additional pad, in particular embodied separately from the connector pad, is arranged on the substrate in the first substrate region and in the second substrate region for connecting at least one contact point to at least one connector pad.

[0008] Due to the multi-piece type of the connector pad and the additional pad, individual arrangements can be carried out, especially at different production time points. When the connector pad is first applied in the first substrate area, then the second substrate area is formed and the additional pad is applied to the first substrate area and the second substrate area subsequently, the connector pad and the additional pad will not be damaged by strong forming during the forming process. The connector pad and / or the additional pad are preferably not formed. Therefore, the electrical connection of the first substrate area and the second substrate area is carried out after the forming of the second substrate area. Therefore, the additional pad is applied smoothly. Therefore, it is ensured that the first substrate area, especially the heating wire, and the second substrate area, especially the contact site are electrically connected to each other.

[0009] In the sense of the invention, a three-dimensional shape is understood to be a shape that deviates from a flat shape at least in sections. A three-dimensional shape can, for example, have a flat section and elevations and / or recesses. In this case, the flat section is not deformed or not deformed or not shaped, and the elevations and / or recesses are deformed or shaped. The flat section still lies in the plane, and the elevations and / or recesses are spaced apart from the plane. Components arranged on the first flat section are protected because they are not shaped.

[0010] Advantageously, the substrate, in particular the first substrate area and / or the second substrate area, and / or the at least one heating wire and / or the at least one connector pad and / or the at least one additional pad, is overmolded. The overmolding may include an IMD (in-mold decoration) or FIM process (film insert molding). The overmolding is preferably performed after the shaping. For the overmolding, a potting material, in particular PC or PET, can be used.

[0011] It is also advantageous if at least one connector pad is bonded and / or soldered to the substrate, in particular to the first substrate region. The connector pad can preferably be designed as a copper pad. The connector pad can preferably be arranged on a double-sided adhesive pad.

[0012] Preferably, the forming of the second substrate region comprises thermoforming and / or thermal deep drawing, in particular vacuum thermoforming and / or high pressure forming.

[0013] An advantageous development provides that the second substrate region is shaped in such a way that after the shaping, the second substrate region is arranged at least in sections at an angle of more than 30°, in particular more than 45° and preferably more than 60° to the film plane. Due to the low expansion capacity, connector pads, in particular copper pads, arranged in the second substrate region can form wrinkles and / or cracks, which can interrupt the electrical connection. The multi-step attachment of the connector pads and the additional pads ensures that wrinkles and / or cracks do not form at these angles, even at these angles.

[0014] Advantageously, the limiting portion of the substrate, i.e. the edge region of the second substrate region adjacent to the first substrate region, has an angle with the membrane plane that is greater than 30°, in particular greater than 45° and preferably greater than 60°. Preferably, the additional pad is applied to the substrate after forming or after forming the limiting portion. Therefore, the additional pad will not be damaged by forming, in particular strong forming at the limiting portion. It is conceivable that at least one connector pad is arranged in the first substrate region and in the second substrate region, and that no connector pad is arranged only in the limiting portion region. After forming, the additional pad can bridge the connector pads arranged in the first substrate region and in the second substrate region by arranging it at the limiting portion.

[0015] Preferably, arranging the heating wire on the substrate comprises an ultrasonic process, in particular an ultrasonic welding process. Here, at least one heating wire is preferably electrically connected to at least one connector pad.

[0016] Advantageously, at least one additional soldering pad is bonded and / or soldered to the substrate, in particular to the first substrate region and the second substrate region. The additional soldering pad can preferably be designed as a copper soldering pad. The additional soldering pad can preferably be arranged on a double-sided adhesive soldering pad.

[0017] In order to further improve the durability of the additional pad, the additional pad may be arranged on the substrate in a meandering manner, especially in the limiting portion.

[0018] It is also advantageous if at least one additional pad is arranged overlappingly on at least one connector pad and / or the additional pad is bonded and / or soldered to the connector pad. Thus, it is ensured that there is a secure electrical connection between the connector pad and the additional pad.

[0019] In order to arrange the at least one additional pad on the substrate, a rolling process and / or a stamping process using a rolling and / or stamping tool can be performed. The rolling process and / or the stamping process is simple and fast. Due to the overlap of the additional pad and the connector pad, high precision is not required during the arrangement.

[0020] The object on which the present invention is based is achieved by a heating film having the features of the present invention. The heating film is produced by the method described above.

[0021] Preferably, the heating film has: - at least one three-dimensional substrate having a first substrate region extending along the film plane and a three-dimensionally deformed second substrate region offset from the film plane; - at least one connector pad arranged on the substrate in a first substrate region; - at least one heating wire arranged on the substrate in the first substrate region and electrically connected to the connector pad; - at least one contact site arranged in or on the substrate in a second substrate region; and - Additional pads which are arranged on the substrate in the first substrate region and in the second substrate region and which electrically connect the at least one connector pad and the at least one contact site.

[0022] Advantageously, the connector pad and / or the additional pad is designed to be non-deformable, ie, not to be deformed during a deformation of the second substrate region.

[0023] It is also advantageous if the substrate and / or the at least one heating line and / or the at least one connector pad and / or the at least one additional pad are injection molded over with a potting material, wherein the potting material comprises in particular PC and / or PET.

[0024] Preferably, the at least one connector pad and / or the at least one additional pad are each designed as a copper pad.

[0025] Advantageously, at least one connector pad and / or at least one additional pad are electrically connected to one another by means of a soldering point.

[0026] It is also advantageous if the second substrate region is arranged at least in sections at an angle of more than 30°, in particular more than 45° and preferably more than 60° to the film plane.

[0027] Preferably, the second substrate region has a stop, which is formed by an edge region of the second substrate region adjacent to the first substrate region. Preferably, the stop is arranged at an angle of more than 30°, in particular more than 45° and preferably more than 60° to the membrane plane. The second substrate region preferably has a flat region, which is preferably configured to be substantially parallel to the membrane plane and spaced apart from the membrane plane. It is conceivable that connector pads can be arranged in the flat region even before shaping. In this case, the additional pad only bridges the stop.

[0028] The content of this specification also relates to a heating film, which includes: - at least one three-dimensional substrate having a first substrate region extending along the film plane and a three-dimensionally deformed second substrate region deviating from the film plane; - at least one connector pad arranged on the substrate in a first substrate region; - at least one heating wire arranged on the substrate in the first substrate region and electrically connected to the connector pad; - at least one contact site arranged in or on the substrate in a second substrate region; and - additional pads which are arranged on the substrate in the first substrate region and in the second substrate region and which electrically connect the at least one connector pad and the at least one contact site; The connector pads and the additional pads are constructed separately from each other.

[0029] The object on which the invention is based is also achieved by a cover for a headlight having the features of the invention. The present description also includes a nose radome having the above-described heating film.

[0030] The present description also includes a method for producing a three-dimensional circuit of an LED lighting device, in particular for a vehicle, in order to form, for example, headlights, direction indicators, exterior decorative lighting elements, lighting devices in the interior of the passenger compartment, background lighting devices for displays and / or for control buttons arranged on the dashboard of the vehicle, etc. Conductive tracks are used instead of heating wires. In this case, the conductive tracks are essentially used for the electrical connection of components, in particular light sources, and not for the generation of heat.

[0031] The method preferably comprises the following steps, preferably performed in the order specified: - providing a substrate extending along the membrane plane, the substrate having a first substrate region for receiving the conductive track and a second substrate region adjacent to the first substrate region, wherein at least one contact site can be or is arranged in the second substrate region; - arranging at least one connector pad on the substrate in the first substrate region; - arranging at least one conductive trace on the substrate in a first substrate region; - connecting at least one connector pad and at least one conductive trace; - shaping the second substrate region to form a three-dimensional shape that deviates from the plane of the film; and At least one additional pad, in particular embodied separately from the connector pad, is arranged on the substrate in the first substrate region and in the second substrate region for connecting at least one contact point to at least one connector pad.

[0032] The circuit may preferably comprise a light source on the substrate.The at least one conductive trace may preferably be electrically connected to a power source.

[0033] The present description also includes a three-dimensional circuit manufactured by the method.

[0034] Further details and advantageous designs of the invention can be found in the following of the description, on the basis of which embodiments of the invention are further described and explained. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 A flow chart of the method according to the present invention is shown; Figure 2 shows a schematic top view of a deformed substrate with a heater line and a copper pad; Figure 3 A cross-sectional view of a vehicle showing a cover with a headlamp; Figure 4 shows a schematic perspective view of a deformed substrate with a deformed connector pad known in the prior art; Figure 5 shows a schematic perspective view of a deformed substrate with undeformed connector pads; and Figure 6 A schematic perspective view of a deformed substrate with undeformed connector pads and undeformed additional pads is shown. DETAILED DESCRIPTION

[0036] according to Figure 3 , a headlamp 10 of a vehicle 12 has a cover plate 14 which is molded onto a bumper 16 and / or onto a not shown hood. A not shown sensor is arranged in the headlamp 10, in particular a sensor for a driver assistance system, the sensor signal of which passes through the cover plate 14 at least once. For this purpose, it is required that a defined wavelength can penetrate the cover plate 14 in order to generate reliable sensor data. For example, water ice and dew are critical for the sensor. For example, the function of the sensor is also ensured by heating in the cover plate 14.

[0037] Heating is provided by a heating film 18. Figures 4 to 6 The heating film 18 comprises a three-dimensional substrate 20, which has a first substrate area 24 extending along a film plane 22 and a three-dimensionally deformed second substrate area 26 deviating from the film plane 22. The second substrate area 26 is further divided into a flat flat area 28 and a stop 30, wherein the stop 30 is formed by an edge area of ​​the second substrate area 26 adjacent to the first substrate area 24. The flat area 28 extends along a deformation plane 32, wherein preferably, the deformation plane 32 extends substantially parallel to the film plane 22. The second substrate area 26 can be configured as a protrusion and / or a recess and / or a step, wherein the stop 30 forms at least one side wall of the protrusion and / or the recess and / or the step.

[0038] according to Figure 3 The limiting portion 30 is arranged at an angle greater than 30°, in particular greater than 45° and preferably greater than 60° to the membrane plane 22 .

[0039] On the substrate 20, according to Figure 5 and Figure 6 , two connector pads 34 are arranged in the first substrate area 24. The connector pads 34 are preferably arranged spaced apart from the second substrate area 26. The connector pads 34 are bonded and / or soldered to the substrate 20. The connector pads 34 are made of copper. The connector pads 34 preferably extend parallel to the membrane plane 22.

[0040] On the substrate 20, according to Figure 5 and Figure 6 In the first substrate area 24, two heating wires 36 are arranged, which are electrically connected to the connector pads 34. The heating wires 36 are preferably made of copper. The heating wires are preferably applied to the substrate 20 by an ultrasonic welding process. Here, the heating wires 36 are also preferably electrically connected to the connector pads 34. Alternatively, the heating wires 36 are bonded and / or soldered to the connector pads 34. The heating wires 36 preferably extend parallel to the membrane plane 22. Figure 2 , three heating wires 36 are shown arranged on the substrate 20 which is not deformed, ie which extends along the film plane 22. The heating wires 36 extend parallel to one another at least in sections. The heating wires 36 lead to the connector pads 34 on both sides.

[0041] On the substrate 20, according to Figure 5 and Figure 6 In addition, two contact points 38 are arranged in the second substrate region 24 for connection to a plug (not shown).

[0042] On the substrate 20, according to Figure 6 An additional solder pad 40 is also arranged, which extends through the first substrate area 24 and the second substrate area 26. The additional solder pad 40 connects the contact site 38 and the connector pad 34 and thus also the heating line 36. The additional solder pad 40 is preferably bonded and / or soldered to the substrate 20. The additional solder pad 40 and the connector pad 34 are electrically connected to each other by means of a soldering site 42.

[0043] When the second substrate region 26 has a planar region 28 having a shape or a shape slightly deviating from a planar shape, it is also conceivable that at least one connector pad 34 is arranged in the first substrate region 24 and at least one connector pad 34 is arranged in the second substrate region 26. In this case, the additional pad 40 merely bridges the stop 30 for connecting the connector pad 34 in the first substrate region 24 and the connector pad 34 in the second substrate region 26.

[0044] The heating wire 36 may be replaced by a conductive track. The additional pad 40 is then used to connect the contact site 38 to an electronic component, in particular to a light source such as an LED or OLED.

[0045] In order to produce the three-dimensionally shaped heating film 18, according to Figure 1 First, a substrate 20 extending along a film plane 22 is provided, the substrate 20 having a first substrate region 24 for receiving at least one heating wire 36 and a second substrate region 26 adjacent to the first substrate region 25. At least one contact site 38 is provided in the second substrate region 26 (S10).

[0046] At least one connector pad 34 is arranged, in particular adhesively bonded and / or soldered, on substrate 20 in first substrate region 24 ( S20 ).

[0047] In addition, at least one heating wire 36 is arranged in the first substrate region 24 on the substrate 20, and the at least one heating wire 36 is connected to the substrate 20, in particular, by means of an ultrasonic welding process (S30). Here, preferably, the at least one heating wire 36 is also electrically connected to the at least one connector pad 34 (S40). Therefore, step S30 and step S40 can also be shown as one step.

[0048] Subsequently, the second substrate region 26 is formed in a first forming process to form a three-dimensional shape that deviates from the film plane 22 (S50). The substrate 20 is formed into a desired shape by means of thermoforming, in particular high pressure forming and / or vacuum thermoforming. Due to the high precision, high pressure forming is preferred. Here, the shape of the heating film 18, in particular the shape of the substrate 20, is molded into the geometric shape of the cover plate 14. A stopper 30 is formed in the second substrate region 26, which is arranged at an angle greater than 30°, in particular greater than 45° and preferably greater than 60° to the film plane 22. In addition, a flat flat region 28 can be formed in the second substrate region 26. Preferably, a contact site 38 is arranged in the flat region 28. The second substrate region 26 can be configured as a protrusion and / or a recess and / or a step, wherein the stopper 30 forms at least one side wall of the protrusion and / or the recess and / or the step.

[0049] Subsequently, at least one additional pad 40 is arranged on the substrate 20 in the first substrate region 24 and in the second substrate region 26 for connecting at least one contact site 38 and at least one connector pad 34 (S60). The additional pad 40 is applied to the substrate 20 in a second forming process, in particular a rolling and / or stamping process. Subsequently, the additional pad 40 can be bonded and / or soldered to the substrate 20. Preferably, the additional pad 40 is arranged on the substrate 20 in such a way that the additional pad 40 overlaps the connector pad 34 at least in sections. The additional pad 40 and the connector pad 34 are preferably connected to each other by means of a soldering site 42.

[0050] Subsequently, the heating film 18, in particular the substrate 20 and / or the connector pads 34 and / or the heating wires 36 and / or the additional pads 40 are preferably overmolded with a potting material 44, such as PC or PET. The overmolding preferably includes in-mold decoration or film insert molding.

[0051] In the prior art, connector pads 34 are applied to the first substrate region 24 and the second substrate region 26 before forming. Figure 4 , warping, wrinkles and / or cracks occur on the connector pad 34 , especially in the area of ​​the limiting portion 30 .

[0052] Due to the separate formation of the connector pad 34 and the additional pad 40, separate arrangements can be made, especially at different production time points (S20, S60). However, the heating wire 38 can be applied to the substrate 20 before forming. When the connector pad 34 is first applied in the first substrate area 24, then the second substrate area 26 is formed and the additional pad 40 is subsequently applied to the first substrate area 25 and the second substrate area 26, neither the connector pad 34 nor the additional pad 40 will be damaged by strong forming during the forming process of the substrate 20. In this case, the connector pad 34 is not formed. The additional pad 40 is preferably molded onto the substrate 20 in a second forming process that is separate from the first forming process. The second forming process can be so adapted to the characteristics of the additional pad 40 that no warping, wrinkles and / or cracks will occur on the additional pad 40. Therefore, the electrical connection of the first substrate area 24 and the second substrate area 26 is performed after the forming of the second substrate area 26. Therefore, the additional pad 40 is applied smoothly. It is thus ensured that the first substrate region 24 , in particular the heating line 36 , and the second substrate region 26 , in particular the contact point 28 , are electrically connected to one another.

Claims

1. A method for producing a three-dimensionally shaped heating film (18), comprising the following steps: Providing a substrate (20) extending along a film plane (22), the substrate (20) having a first substrate region (24) for receiving a heating wire (36) and a second substrate region (26) adjacent to the first substrate region (24), wherein at least one contact point (38) can be or is arranged in the second substrate region (26); Arranging at least one connector pad (34) on the substrate (20) in the first substrate region (24); Arranging at least one heating wire (36) on the substrate (20) in the first substrate region (24); connecting the at least one connector pad (34) and the at least one heating wire (36); shaping the second substrate region (26) to form a three-dimensional shape that deviates from the film plane (22); and At least one additional pad (40) is arranged on the substrate (20) in the first substrate region (24) and in the second substrate region (26) for connecting the at least one contact site (38) and the at least one connector pad (34).

2. The method according to claim 1, wherein: The substrate (20) and / or the at least one heating wire (36) and / or the at least one connector pad (34) and / or the at least one additional pad (40) are injection molded.

3. The method according to claim 1 or 2, wherein: The at least one connector pad (34) is bonded and / or soldered to the substrate (20).

4. A method according to any one of the preceding claims, wherein: Shaping the second substrate region (26) includes hot forming and / or hot deep drawing.

5. A method according to any one of the preceding claims, wherein: The second substrate region (26) is shaped in such a way that the shaped second substrate region (26) is at least partially arranged at an angle of more than 30°, in particular more than 45° and preferably more than 60° to the film plane (22).

6. A method according to any one of the preceding claims, wherein: Arranging the heating wire (36) on the substrate (20) includes an ultrasonic process.

7. A method according to any one of the preceding claims, wherein: The at least one additional soldering pad (34) is bonded and / or soldered to the substrate (20).

8. A method according to any one of the preceding claims, wherein: The at least one additional pad (40) is arranged on the substrate (20) in a meandering manner.

9. A method according to any one of the preceding claims, wherein: The at least one additional soldering pad (40) is arranged overlappingly on the at least one connector soldering pad (34), and / or the additional soldering pad (40) is bonded and / or soldered to the connector soldering pad (34).

10. A method according to any one of the preceding claims, wherein: Arranging the at least one additional pad (40) on the substrate (20) comprises a rolling process and / or a stamping process.

11. A heating film (18) produced using the method according to any one of the preceding claims, the heating film (18) comprising in particular: at least one three-dimensional substrate (20), the three-dimensional substrate (20) having a first substrate region (24) extending along a membrane plane (22) and a three-dimensionally deformed second substrate region (26); at least one connector pad (34) disposed on the substrate (20) in the first substrate region (24); At least one heating wire (36) is arranged on the substrate (20) in the first substrate region (24) and is electrically connected to the connector pad (34); at least one contact site (38) arranged in the substrate (20) or on the substrate (20) in the second substrate region (26); as well as At least one additional pad (40) is arranged on the substrate (20) in the first substrate region (24) and in the second substrate region (26) and electrically connects the at least one connector pad (34) and the at least one contact site (38).

12. The heating film (18) according to claim 11, wherein: The substrate (20) and / or the at least one heating wire (36) and / or the at least one connector pad (34) and / or the at least one additional pad (40) are injection-molded with a potting material (44), wherein the potting material (44) in particular comprises PC and / or PET.

13. The heating film (18) according to claim 11 or 12, wherein: The at least one connector pad (34) and / or the at least one additional pad (40) are each designed as a copper pad.

14. The heating film (18) according to any one of claims 11 to 13, wherein The at least one connector pad (34) and / or the at least one additional pad (40) are electrically connected to one another by means of a soldering point (42).

15. The heating film (18) according to any one of claims 11 to 14, wherein The second substrate region (26) is at least partially arranged at an angle of greater than 30°, in particular greater than 45° and preferably greater than 60° to the film plane (22).

16. A cover plate (14) for a headlamp (10), comprising a heating film (18) according to any one of claims 11 to 15.

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