SYSTEM FOR CONNECTING A FLAT BODY TO A POWER SUPPLY, INCLUDING AN INTEGRATED CONTROL UNIT

Description

[0001] The invention relates to an arrangement for connecting a flat body to a power supply, with a ribbon cable, a control unit and a connection element, wherein the power supply is provided at least for supplying the control unit with an electrical voltage and the flat body has an electrically conductive structure, a button for generating a control signal and the control unit is provided for receiving the control signal.

[0002] Flat surfaces, such as vehicle windows, are equipped with at least one electrically conductive structure to offer additional functionality. This additional functionality can include electric window heating or integrated rain sensors. In living spaces, flat surfaces are commonly found as wall-mounted radiators or heated mirrors.

[0003] To control its functionality, the surface body features a button that allows a user to operate the function. These buttons can be designed as capacitive touch controls in the form of line or surface electrodes. Touching the button generates a control signal that is transmitted via an electrical connection to a control unit. The control unit then executes a function dependent on the control signal.

[0004] EP 2669083 A1 describes a flat body with a connection assembly that electrically connects an electrically conductive structure of the flat body to an external electrical connection. The connection assembly comprises a ribbon cable with a ribbon conductor made of an electrically conductive material and surrounded by a sheath of an electrically insulating material. The ribbon conductor is electrically connected at one end to the electrically conductive structure of the flat body and at its other end to a round conductor.

[0005] This connection of the flat conductor to the round conductor forms a connection zone, which is embedded in a sealant compound surrounded by a connection housing. The round conductor terminates in a connection element, for example, an electrical plug.

[0006] For physical reasons, flat and round conductors generate undesirable parasitic losses. These losses arise from capacitive coupling with the environment and are also known as parasitic capacitance. This parasitic capacitance can generate an unwanted switching signal from the button.

[0007] DE 10 2011 121921 A1 discloses an arrangement for heating a vehicle windshield with a surface heating element connected to the vehicle's electrical system via a connecting cable. Furthermore, D1 discloses a sensor unit for acquiring data relevant to the windshield heating. A humidity sensor unit is either bonded to the connecting cable or integrated into the plastic matrix of the connecting cable during its manufacture. The humidity sensor unit is electrically connected to an electronic heating control unit, which in turn is electrically connected to an electronic switch unit for controlling the windshield heating.

[0008] DE 101 32 963 C1 discloses a clamping device for fastening glass panes, comprising two clamping elements that can be attached to a glass pane. The clamping elements have two clamping pads on their inner surfaces, which can be clamped against each other by a clamping screw. Furthermore, the clamping device has a flexible, mechanically compliant electrical connection with a multi-pole plug connector for multi-layered glass panes with an electrical conductor arrangement.

[0009] WO 2015 / 162107 A1 discloses a disc with an illuminated button and heating function. The disc has a transparent substrate and a heating area connected to two busbars for connection to a voltage source.

[0010] The object of the present invention is to provide an improved arrangement for connecting a flat body to a power supply which has a reduction in parasitic losses.

[0011] The object of the present invention is achieved according to the invention by an arrangement for connecting a flat body to a power supply and a flat body with an arrangement according to independent claim 1. Preferred embodiments are described in the dependent claims.

[0012] A method according to the invention for manufacturing the arrangement is described in further claims.

[0013] The present invention comprises an arrangement for connecting a flat body to a power supply, comprising a ribbon cable, a control unit, and a connection element. The power supply is provided at least for supplying the control unit with an electrical voltage. The flat body has an electrically conductive structure and a button for generating a control signal. The control unit is provided for receiving the control signal and is embedded in an insulating material between the flat body and the connection element.

[0014] Such arrangements feature shortened cabling between capacitively sensitive surface bodies and power supply, so that the button is well protected against parasitic capacitances of the cabling.

[0015] The flat body can contain materials such as glass or plastic and can be designed as a single-pane glass unit or as a laminated unit with two individual panes firmly bonded together by a thermoplastic adhesive film. For example, the flat body could be a laminated unit with an electric heating element or an antenna conductor.

[0016] The electrically conductive structure of the flat body can be electrically connected to a power supply via the ribbon cable and the connection element. According to the invention, a "ribbon cable" is understood to be a single- or multi-core cable. The ribbon cable has several flat conductors that are held parallel to each other at a distance from one another along the ribbon cable by a sheathing made of insulating material (e.g., polyamide or Kapton). A flat conductor can, for example, be a ribbon- or strip-shaped conductor made of metal foil with a very small layer thickness in the single- or double-digit micrometer range.

[0017] A function of the surface body can be controlled by touching the button. Such buttons can be designed as line or surface electrodes, or as capacitive buttons using two coupled electrodes, and operate according to so-called touch control technology. For example, the surface body's electrical heating element is controlled via this button.

[0018] When an object, preferably a human finger, approaches the button, the capacitance of the electrodes changes due to the object's electrical charge. This change in capacitance causes charge transfer, resulting in an electric current flowing and thus generating a control signal for the control unit. This control signal can be a switching signal to turn the heating device on or off.

[0019] The control unit is designed to receive the control signal. The control unit is preferably a microchip (IC) that can be mounted on a printed circuit board (PCB). Such circuit boards may contain other electronic components. The control unit preferably includes sensor electronics, in particular capacitive sensor electronics, for controlling the functionality of the surface body.

[0020] The sensitivity of the sensor electronics is set such that it outputs a control signal when the switching area is touched by one or more human fingers. Touching the switching area can also be understood as any other type of interaction with the switching area that generates a change in capacitance. Preferably, the control signal is triggered only when a substrate side of the surface body is touched.

[0021] The control unit is embedded in an insulating material between the surface body and the connection element. Such arrangements result in a close proximity between the control unit and the surface body, and thus a shortened, fixed length of the ribbon cable. This advantageously decouples the parasitic capacitances from the button and reduces losses. Adjusting the button's sensitivity is therefore simplified.

[0022] Advantageously, subsequent adjustment of the button's sensitivity due to variations in cable length can be avoided with low losses.

[0023] According to the invention, the arrangement comprises a housing with a conductor connection between an electrical conductor and a flat ribbon conductor running within the flat ribbon cable, with the control unit being located in the housing. A further improvement of the arrangement is that the control unit forms a stable connection with the housing. Such housings are made of plastic, for example polyimide, and comprise an insulating material comprising a polymer. The insulating material has properties that shield the control unit from the external environment in an airtight and watertight manner.

[0024] According to the invention, the housing includes an adjustment means for adapting the sensitivity of the control unit. Such adjustment means are provided for changing an internal comparator capacitance of the control unit. One reason for changing the comparator capacitance could be a modified design of the electrodes in the button.

[0025] For example, the adjustment means could be a connecting element, such as a screw, whose screw head can be easily accessible from outside the housing. Alternatively, the adjustment means could be an additional parallel ribbon cable or terminal on the housing.

[0026] In a further advantageous embodiment of the invention, the connection element for networking the surface body in a vehicle or device can be provided. The connection element can thus be a serial interface of a bus system, for example a CAN bus system, of the vehicle.

[0027] In a further advantageous embodiment of the arrangement according to the invention, the control unit is arranged at least partially within the ribbon cable. In particular, the control unit is embedded in the insulating material of the ribbon cable. The control unit is in direct electrical contact with at least one ribbon conductor.

[0028] The insulation material of the flat ribbon cable can be made of plastic, e.g., polyimide. This arrangement allows the number of special (OEM-specific) connection elements, which must be specifically adapted to the installation environment of the flat body, to be reduced to a single connection element.

[0029] Advantageously, the control unit includes an adjustment mechanism for adapting its sensitivity. This adjustment mechanism can be a capacitor whose capacitance can be adapted to the geometric design of the flat ribbon conductor and the electrically conductive structure.

[0030] Furthermore, the invention relates to a planar body according to claim 8.

[0031] Such a flat body requires very little space for storage, transport, and installation in a vehicle or device.

[0032] The invention also relates to a method for manufacturing an arrangement according to claim 9.

[0033] In an advantageous embodiment of the method, an electrical conductor is electrically connected to a flat ribbon conductor running within the flat ribbon cable. The connection between the conductor and the flat ribbon conductor, as well as the control unit, are arranged and fixed in a housing. The housing is then potted with insulating material. Alternatively, a protective lacquer can be applied to the control unit before potting it with insulating material.

[0034] Advantageously, the housing is formed from two half-shells. A first half-shell, filled with insulating material, is designed to hold the conductor connected to the ribbon cable and the control unit. In a further process step, a second half-shell is placed on top of the first, so that a box-shaped housing is formed by the first and second half-shells.

[0035] It is also conceivable that the connection between the conductor and the flat ribbon conductor, as well as the control unit, are encased by the insulating material in a first process step and then enclosed in a second process step by an encapsulating, one-piece molded housing inside the housing.

[0036] In a further advantageous embodiment of the method, the control unit is at least partially embedded in the insulation material of the ribbon cable. It is preferred that the control unit is embedded in the insulation material of the ribbon cable by means of lamination.

[0037] Additionally, the control unit can be encased by another layer. This layer is preferably a flexible film made of an electrically conductive material, which advantageously protects the control unit from damage. Furthermore, the film can at least partially encase the control unit and advantageously influence the electromagnetic compatibility (EMC) of the arrangement.

[0038] The invention will now be explained in more detail with reference to figures and exemplary embodiments. These figures show: Fig. 1 a schematic view of a first embodiment of an arrangement for connecting a flat body Fig. 2 a schematic view of a second embodiment of an arrangement for connecting a flat body Fig. 3 a cross-section of a flat ribbon cable with embedded control unit Fig. 4 a flowchart of an exemplary method for manufacturing an arrangement according to the invention, in which a control unit is embedded in an insulating material of a flat ribbon cable.

[0039] Figure 1Figure 1 shows a first embodiment of an arrangement 1 for connecting a flat body to a power supply. The flat body is a laminated disc 2, which is formed from two individual discs. The individual discs are firmly bonded together by a thermoplastic adhesive film. The individual discs are preferably made of glass; alternatively, the individual discs can be made of non-glass material, for example, plastic.

[0040] The composite disc 2 has an electric heating element or other functionality that is powered via an electrically conductive structure with a corresponding voltage supply for operating the composite disc 2. The electrically conductive structure is integrated into the composite disc 2 in the form of several busbars.

[0041] Furthermore, the composite disc 2 has a button integrated into the composite disc, which can be formed from the same conductive structure as that of the heating function, via which, for example, the heating device can be controlled.

[0042] The button and the heating element are electrically and optically separated from each other on the laminated glass. The button can be operated with a standard vehicle power supply, e.g., 12V or 48V (vehicle electrical system), whereby the heating element should be supplied with a corresponding heating voltage.

[0043] Such buttons can be designed as line or surface electrodes, or as capacitive buttons using two coupled electrodes, and operate according to so-called touch control technology. The button is preferably located at the outer edge of the composite disk 2, close to one of the busbars, and in a heating application is preferably oriented parallel to the current direction in order not to affect the homogeneity of a heating layer.

[0044] When an object, preferably a human finger or an element with similar permittivity properties, approaches the button, the capacitance of the electrodes changes due to the object's electrical charge. This change in capacitance causes charge transport. An electric current flows and generates a control signal. This control signal is a switching signal that can, for example, control the switching on or off of a heating device.

[0045] The control signal is transmitted to a control unit 7 via an electrical connection 3. For this purpose, the button is electrically connected to a flat conductor 5 of a two-core flat cable 4. A flat conductor 5, also called a foil conductor or flat conductor, is an electrical conductor whose width is significantly greater than its thickness. The flat conductor 5 is electrically insulated with an insulating material 8, for example, a polyimide layer, and is routed to the outside as a flat cable 4 over the edge of the composite disc 2.

[0046] The ribbon cable 4 terminates in a housing 9, in which the ribbon conductor 5 is electrically connected to a conductor, for example, a round conductor 10. The control unit 7 is also located in the housing 9 and is electrically connected to the ribbon conductor 5 or round conductor 10, so that the control unit 7 can receive and evaluate the control signal generated at the button. The housing 9 is at least partially filled with an insulating material in which the control unit 7 is embedded.

[0047] The control unit 7 is preferably a capacitive sensor electronics for controlling the touch control technology. The sensor electronics can be a microchip mounted on an electronic circuit board (PCB) 12 as shown in Figure 3 The diagram shows how the circuit boards are arranged. Such electronic circuit boards may also contain other electronic components.

[0048] The housing 9 has a screw 11 or other connecting element that serves as an adjustment means for adapting the sensitivity of the control unit 7. The screw head of the screw 11 is easily accessible from the outside of the housing surface. In this way, the sensitivity of the control unit 7 can be adjusted even when the housing is closed.

[0049] The round conductor 10 is led out of the housing 9 through an opening and is electrically connected at its second end to a connecting element 6.

[0050] The connection element is designed for contacting the composite disk 2 in a vehicle electronics system. The connection element is vehicle-specific or designed as a plug compatible with a vehicle bus system. For example, the connection element can be a serial interface of a CAN bus system in the vehicle.

[0051] Figure 2Figure 1 shows a second embodiment of an arrangement 1' for connecting a surface body. Analogous to the embodiment in Figure 2. Figure 1 The composite disc 2 has an electric heating element that is electrically connected to the power supply via the busbars. Furthermore, the composite disc 2 has an integrated button that can be used to control the heating element or any other function. For this purpose, the button is electrically connected to the ribbon conductor 5.

[0052] In contrast to the exemplary embodiment of the Figure 1 The arrangement 1' indicates Figure 2 There is no housing 9 in which the control unit 7 could be accommodated. Furthermore, the control unit 7 is electrically contacted with the ribbon cable 5. In the second embodiment, the control unit 7 is embedded in the insulating material 8 of the ribbon cable 4.

[0053] The ribbon cable 4 ends with the connection element 6, which in turn is designed as a plug suitable for the installation environment of a vehicle.

[0054] Figure 3 shows a cross-section of the flat ribbon cable 4 made of Figure 2 with embedded control unit 7. The flat ribbon cable 4 has an unshielded area of ​​the flat ribbon conductor 5 at its first end. This area serves to contact the flat ribbon conductor 5 with a contact point of the sensitive structure of the composite disk 2.

[0055] The flat ribbon conductor 5 is electrically contacted between its first end, which is connected to the conductor connection 3 of the composite disc 2, and its second end, which is connected to the control unit 7 embedded in the insulating material 8. The flat ribbon cable 4 terminates at its second end in the connection element 6, which serves as a plug for connecting to the vehicle's installation environment.

[0056] Figure 4Figure 1 shows a flowchart of an exemplary method for manufacturing an arrangement 1' according to the invention, in which in a first step a flat body 2 with an electrically conductive structure 3 is provided and with which a flat ribbon conductor 5 of a flat ribbon cable 4 is electrically connected.

[0057] In the second step, a control unit 7 is positioned on the flat conductor 5 between the flat body 2 and the connection element 6. In a third step, the control unit 7 is connected to the flat conductor 5. In a further step, the control unit 7 and the flat conductor 5 are embedded in the insulating material 8'. The control unit 7 is encased in the insulating material of the flat cable by means of lamination.

[0058] Additionally, the control unit 7 can be encased by another layer. This layer is preferably a flexible film made of an electrically conductive material. Reference symbol list:

[0059] 1 a first embodiment of an arrangement 1' a second embodiment of the arrangement 2 composite disc 3 conductor connection 4 ribbon cable 5 ribbon conductor 6 connection element 7 control unit 8 insulation material 8' insulation material of the ribbon cable 9 housing 10 electrical round conductor 11 screw 12 electronic circuit board

Claims

1. Assembly (1, 1') for connecting a flat body (2) to a voltage supply, having a ribbon cable (4), a control unit (7), and a connection element (6), wherein the voltage supply is provided at least to supply the control unit (7) with an electric voltage and the flat body (2) has - an electrically conductive structure (3) , - a capacitive switching surface for generating a control signal, and the control unit (7) is provided to receive the control signal, - wherein the assembly has a housing (9) with a line connection between an electrical conductor (10) and a flat strip conductor (5) running in the ribbon cable (4) - wherein the control unit (7) is arranged in the housing (9), characterized in that the control unit (7) is embedded in an insulating material (8, 8') between the flat body (2) and the connection element (6) and that the housing (9) has a setting means (11) for adjusting a sensitivity of the control unit (7).

2. Assembly (1) according to claim 1, wherein the connection element (6) is provided to network the flat body (2) in a vehicle.

3. Assembly (1) according to claim 2, wherein the connection element (6) is a serial interface of a bus system of the vehicle.

4. Assembly (1') according to claim 1, wherein the control unit (7) is arranged at least partially in the ribbon cable (4).

5. Assembly (1') according to claim 4, wherein the control unit (7) is embedded at least partially in the insulating material (8') of the ribbon cable (4).

6. Assembly (1') according to claim 4, wherein the control unit (7) has a setting means, in particular a capacitor, for adjusting a sensitivity of the control unit (7).

7. Assembly (1') according to claim 1, wherein the control unit (7) has an electronic board with at least one electronic component and a connecting interface.

8. Flat body (2) with an assembly according to one of claims 1 through 7 for connecting the flat body to a voltage supply of a vehicle, which is provided at least to supply the control unit (7) with an electric voltage.

9. Method for producing an assembly according to claim 1, wherein the control unit (7) is embedded in an insulating material (8) between the flat body (2) and the connection element (6).

10. Method according to claim 9, wherein - an electrical conductor (10) is electrically conductingly connected to a flat strip conductor (5) running in the ribbon cable (4), - the connection between the conductor (10) and the flat strip conductor (5) and the control unit (7) are arranged and secured in a housing (9), and - the housing (9) is cast with the insulating material.

11. Method according to claim 9, wherein the control unit (7) is at least partially embedded in the insulating material (8') of the ribbon cable (4).

12. Method according to claim 11, wherein the control unit (7) is embedded in the insulating material (8') of the ribbon cable (4) by lamination.