Electrical heating and capacitive sensing device and method of manufacturing the same

Abstract

An electrical heating and capacitive sensing device, comprising: an electrically conductive heating track arranged on a surface of a planar substrate, the conductive track being connectable to a current source so that current flows through the conductive track during a heating operation, and the conductive track being connectable to a capacitive sensing circuit so that a capacitive sensing signal is applied to the conductive track during a sensing operation. The conductive track comprises at least a first heating track segment and a second heating track segment extending at a distance from each other on the substrate, thereby forming a gap between the first heating track segment and the second heating track segment. The heating and sensing device further comprises a layer of electrically conductive material on the surface of the substrate arranged in the gap between the first heating track segment and the second heating track segment.

Description

Technical Field

[0001] The present invention relates to an electric heating and capacitive sensing device, in particular for automotive applications, and a method of manufacturing such an electric heating and capacitive sensing device. Background Art

[0002] In the field of automotive sensor applications, it is known to use sensors for so-called hands off detection (HOD) systems, wherein one or several sensors provide information about whether the driver's hands are on the steering wheel. This information can be provided as input to an Automatic Driver Assistance System (ADAS), such as an Adaptive Cruise Control (ACC), which can warn the driver based on the provided sensor signal and remind him to regain control of the steering wheel again. It is also known to use capacitive sensors in HOD systems, wherein the capacitive sensors are used to detect the presence and / or position of a conductor or conductor portion in the vicinity of an antenna electrode.

[0003] As used herein, the term "capacitive sensing device" refers to a sensor that generates a signal in response to the effect of a sensed object (a person, a part of a person's body, a pet, an object, etc.) on an electric field. In general, a capacitive sensing device typically includes at least one antenna electrode to which an oscillating electrical signal is applied while the sensing device is in operation and which subsequently transmits an electric field into a spatial region adjacent to the antenna electrode. The sensor includes at least one sensing electrode, which may be the same as or different from the transmitting antenna electrode, at which the effect of an object or a living being on the electric field is detected.

[0004] In some (so-called "loaded mode") capacitive sensors, the at least one antenna electrode is simultaneously used as a sensing electrode. In this case, the measurement circuit determines the current flowing into the at least one antenna electrode in response to an oscillating voltage being applied to the at least one antenna electrode. The relationship between the voltage and the current produces a complex impedance between the at least one antenna electrode and the ground potential. In an alternative version of the capacitive sensor (a "coupled mode" capacitive sensor), the transmitting antenna electrode and the sensing electrode are separated from each other. In this case, the measurement circuit determines the current or voltage induced in the sensing electrode when the at least one transmitting antenna electrode is being operated.

[0005] Capacitive sensing devices are often arranged near electric heating devices included in vehicle seat heaters or vehicle steering wheel heaters. Since heater components, such as heater wires, are regularly electrically connected to vehicle ground, they may have a significant influence on the capacitive sensor signal to be measured.

[0006] Electric heating devices are widely used in the automotive industry. The basic necessity of such heating devices is that they are not visible or perceived by the vehicle user as long as the heating device is not working. Generally speaking, the electric heating device can be integrated in or covered by another component, such as a decorative cover of the steering wheel. Another requirement is to provide uniform or consistent heating after the heating device has been activated, for example heating at a predetermined heating rate of several degrees Celsius within a specified time interval. Uniform heating prevents the generation of hot spots and / or cold zones. These requirements generally prohibit the use of conventional heating wires, such as heating wires based on copper or copper-nickel (manganese) based alloys, which provide a relatively low temperature dependence of the resistivity and may also be perceived by the driver. Summary of the invention

[0007] Purpose of the Invention

[0008] It is therefore desirable to provide an improved electric heating and capacitive sensing device, in particular for automotive applications, wherein the electric heating and sensing device prevents the occurrence of hot spots during heating operation while providing enhanced sensing functionality. This object is achieved by the subject matter of the independent claims. SUMMARY OF THE INVENTION

[0010] In one aspect of the invention, the object is achieved by an electrical heating and capacitive sensing device, the device comprising: a planar substrate; an electrically conductive heating track arranged on a surface of the substrate, the conductive track being connectable to a current source so that a current flows through the conductive track during a heating operation. The conductive track is connectable to a capacitive sensing circuit so that a capacitive sensing signal is applied to the conductive track during a sensing operation. The conductive track comprises at least a first heating track section and a second heating track section extending at a distance from each other on the substrate, thereby forming a gap between the first heating track section and the second heating track section. The heating and sensing device further comprises a layer of electrically conductive material on the surface of the substrate arranged in the gap between the first heating track section and the second heating track section. The width of the layer of electrically conductive material is smaller than the width of the gap between the first heating track section and the second heating track section. The layer is arranged to be separated from the first heating track section and the second heating track section. The heating and sensing device also includes a door member of conductive material, which is arranged within a portion of the gap and extends between the conductive material layer and a single one of the first heating track segment and the second heating track segment so as to locally connect the conductive material layer to the one of the first heating track segment and the second heating track segment.

[0011] The term "substrate" generally refers to a material having a flat shape configured to support an electrically conductive heating track. The substrate may, for example, comprise a plastic foil comprising at least one of: polyethylene terephthalate (PET), thermoplastic polyurethane (TPU), polyurethane (PU), plastic, polymer or a mixture thereof.

[0012] The term "separation" generally refers to spatial separation or isolation. Due to the different widths, a channel-like structure is formed between the conductive material layer and the first heating track segment and the second heating track segment. Therefore, the conductive material layer can be spatially separated from the conductive heating track (respectively from the first heating track segment and the second heating track segment).

[0013] The term "gate member" generally refers to an element formed of an electrically conductive material. It should be noted that the gate member may extend substantially in the extension direction of the first track segment and the second track segment. The extension of the gate member relative to the electrically conductive material layer may be particularly small, so that an electrical sensing signal may pass through the gate member from the corresponding heating track segment without a heating current flowing through the electrically conductive material layer.

[0014] The term "local" generally refers to a specific location, respectively, the location of the door member formed in a narrow channel-like structure between the conductive material layer and the first heating track or the second heating track. The door member may be arranged in a portion of the gap between the conductive material layer and the first heating track segment or the second heating track segment. In other words, the door member may be in contact with the conductive material and one of the adjacent heating track segments.

[0015] One advantage of the proposed electrical heating and capacitive sensing device is that, due to the small size of the gate member, the electrical sensing signal can pass through the gate member while the flow of electrical heating current to the conductive material layer is blocked. This can allow that during capacitive sensing operation, the conductive layer providing a relatively high surface conductivity can be used as part of an antenna that helps to generate an active area of ​​the capacitive sensing device. In other words, during capacitive sensing operation, the active area of ​​the electrical heating and capacitive sensing device can be defined by the heating track as well as the conductive layer.

[0016] Another advantage of the proposed electric heating and capacitive sensing device is that its structure is not easily perceived by the user. Since the layer of conductive material is filled in the gap between the first heating track section and the second heating track section, there is no depth between adjacent heating tracks to generate a perceptible bend. The heating device can also advantageously be mounted under a cover such as a textile steering wheel cover.

[0017] Another advantage of the proposed electric heating device is that an enhanced uniformity in heat dissipation can be provided during the heating operation due to the layer of conductive material arranged between the heating track sections. The conductive material on the substrate between the heating tracks can provide a function similar to a thermal bridge. The conductive layer can facilitate heat transfer, for example conduction-based heat transfer, by providing a path with only a small resistance for heat transfer originating from the heating tracks and / or the heated substrate. As a result, the thermal resistance of the electric heating device is reduced, and the thermal energy provided by the heating tracks can be uniformly dissipated via the layer of conductive material, respectively the surface of said material. As a result, the generation of hot spots caused by the heating tracks and / or cold zones caused by the gaps can be reduced or completely prevented.

[0018] The invention is particularly useful in the field of automotive applications, but may also be advantageously used in building construction or medical applications.The term "automobile" as used in this patent application is to be understood in particular as applying to vehicles including passenger cars, trucks, semi-trucks and buses.

[0019] In a preferred embodiment, the door member, the conductive heating track and / or the conductive material layer are formed of the same material. In the case where the door member, the conductive heating track and / or the conductive material layer are made of the same material, the electric heating and capacitive sensing arrangement can provide increased uniformity in terms of capacitive sensing. Alternatively, the door member, the conductive heating track and / or the conductive material layer can be formed of different materials.

[0020] It should be appreciated that, in order to prevent the heating current from dissipating through the conductive material layer during the heating operation, the length extension of the gate member in the extension direction of the first track section and the second track section should be substantially less than the length extension of the conductive material layer in this direction. The length extension of the gate member can be, for example, at least 50 times smaller than the length extension of the conductive material layer in this direction, preferably at least 100 times smaller than the length extension of the conductive material layer, and even more preferably at least 200 times smaller than the length extension of the conductive material layer. In a possible embodiment where the conductive material layer extends a distance of 50cm, the gate member preferably has a length within a range of several mm, for example, between 1mm and 10mm. Since the length of the gate member is particularly small, no heating current can pass through the gate member to reach the conductive material layer, but the gate member enables the conductive layer to be used as an active sensing area during the capacitive sensing operation. It should be appreciated that the length extension of the gate member should be high enough to enable a low ohmic path between the conductive material layer and the corresponding heating track section, and to withstand mechanical stress during installation or assembly. This means that the length of the gate member can depend on the installation process of the device. For example, in cases where it is expected that high stresses may be applied to the electric heating and capacitive sensing device during its installation on another component, such as a steering wheel, the door member may also be constructed to have a length of about 3 mm. A door member with a length of 3 mm or more may provide a higher resistance to external mechanical forces. At the same time, the length extension of the door member should be low enough to avoid resistance variations of the entire heating track and the second heating track section. This requirement is best achieved if the length extension of the door member is preferably at least 200 times smaller than the length extension of the conductive material layer.

[0021] In a preferred embodiment, the thickness of the layer of conductive material and the thickness of the first heating track segment and / or the second heating track segment are substantially equal. The term "thickness" may refer to the height dimension of the heating track relative to the surface of the substrate. Since the layer of conductive material and the first heating track segment and / or the second heating track segment have the same thickness, the electrical heating and capacitive sensing device are not easily perceived by the user. In addition, equal thickness may also result in more consistent heat dissipation and enhanced uniformity of the capacitive sensing function.

[0022] In a preferred embodiment, the substrate comprises a conductive fabric or foil. The use of a fabric or foil may enhance the stretchability, corresponding ductility and flexibility of the electrical heating and capacitive sensing device. Thus, it is facilitated to mount the electrical heating and capacitive sensing device on another component, for example on a steering wheel.

[0023] In an embodiment, an insulating material may be arranged on the surface of the substrate between the layer of conductive material and the first heating track segment and / or the second heating track segment. The insulating material may have relatively weak insulating properties, so that a certain predeterminable amount of heat may be dissipated through the insulating material. In addition, the insulating material may also prevent a short circuit between the layer of conductive material and the first heating track segment and / or the second heating track segment. Furthermore, the arrangement of the insulating material on the surface of the substrate between the layer of conductive material and the first heating track may further contribute to the perception of perceptible inhomogeneities, respectively bends.

[0024] In a preferred embodiment, each of the first heating track section and the second heating track section has a first wavy shape extending along the length direction of the electric heating device. The term "length direction" may refer to a direction defined by the length dimension of the electric heating and capacitive sensing device. The wavy shape may further increase the stretchability of the heating device. In addition, the wavy shape further enhances the uniformity of heat dissipation.

[0025] In a preferred embodiment, the first heating track segment has an inner radius relative to an inner vertex at a first edge of the heating track segment, wherein the inner radius extends over a portion of the first heating track segment to a second edge of the first heating track segment; and wherein the first heating track segment has an outer radius relative to an outer vertex at the second edge, wherein the outer radius extends over a portion of the gap to a first edge of the second heating track segment; and wherein the inner radius and the outer radius are equal. The term "vertex" may refer to a peak point on an edge of a heating track segment. For example, a vertex may be a point on an edge where the edge has no slope. The mathematical term "slope", respectively gradient, may refer to a number describing the direction and steepness of a line. The inner radius may extend from the first edge of the first heating track segment over a portion of the first heating track segment. Further for example, the inner vertex and the outer vertex may be aligned with each other. The outer radius may extend from the second edge of the first heating track segment over a portion of the gap, respectively the conductive material arranged in the gap, to the first edge of the second heating track segment. This arrangement may allow for particularly uniform heat transfer from the heating track segment to the conductive material, while further enhancing stretchability.

[0026] In a preferred embodiment, the conductive track comprises at least one of: Cu, Ni, Ag, Al or a mixture thereof. A heating track comprising copper (Cu), nickel (Ni), silver (Ag) or aluminum (Al) may provide enhanced electrical and thermal conductivity.

[0027] In a preferred embodiment, the electrically conductive heating track comprises a plurality of heating traces electrically connected to each other in parallel, wherein a first heating trace of the plurality of heating traces comprises a first heating track segment, and wherein a second heating trace of the plurality of heating traces comprises a second heating track segment. The arrangement of several heating traces may further enhance particularly fast heat dissipation and allow a particularly large active sensing area to be provided.

[0028] In a preferred embodiment, the electrically conductive heating track has a meander shape or a U-shape, wherein the first heating track segment and the second heating track segment are formed by adjacent branches of the meander shape or the U. The first heating track segment and the second heating track segment may each form a branch, respectively, a segment, of the meander shape or the U. The meander shape or the U-shape of the heating track allows for a relatively large coverage of the area to be heated and also provides for an enlarged active area.

[0029] In an embodiment, the electric heating and capacitive sensing device may include a control unit configured to determine the heating power applied to the heating and sensing device by contacting the conductive track with the terminals. The control unit may also be configured to handle capacitive sensing. In addition, the control unit may, for example, allow switching between heating operation and capacitive sensing operation.

[0030] In another aspect of the invention, the object is achieved by a steering wheel heater for automotive applications, comprising an electric heating and capacitive sensing arrangement according to the invention. The steering wheel heater further comprises: a current source connectable to contact terminals of the electrically conductive heating track; a control unit configured to connect said current source to said terminals to control the heating operation accordingly; and a capacitive sensing circuit for sending said capacitive sensing signal.

[0031] The benefits described in the context of the proposed electrical heating and capacitive sensing arrangement according to the invention fully apply to the proposed steering wheel heater as well.

[0032] According to another aspect, the present invention relates to a method of manufacturing an electric heating and capacitive sensing device, the method comprising at least the following steps: providing a planar substrate, applying an electrically conductive heating track on a surface of the substrate, the electrically conductive heating track comprising at least a first heating track section and a second heating track section, the first heating track section and the second heating track section extending at a distance from each other on the substrate, thereby forming a gap between the first heating track section and the second heating track section. The method further comprises the following steps: applying a layer of electrically conductive material on the surface of the substrate in the gap, wherein the width of the layer of electrically conductive material is smaller than the width of the gap between the first heating track section and the second heating track section, wherein the layer of electrically conductive material is located on the substrate so as to be separated from the first heating track section and the second heating track section. The method further comprises the following steps: applying an electrically conductive material so as to form a gate member on the surface of the substrate in the gap, wherein the gate member is arranged in a portion of the gap and extends between the layer of electrically conductive material and a single one of the first heating track section and the second heating track section so as to locally connect the layer of electrically conductive material to the one of the first heating track section and the second heating track section.

[0033] The benefits described in the context of the proposed electrical heating and capacitive sensing arrangement according to the invention fully apply to the proposed method as well.

[0034] The invention also relates to a further method of manufacturing an electrical heating and capacitive sensing device, the method comprising at least the steps of providing a planar substrate, applying a layer of conductive material on a surface of the substrate, selectively removing portions of the conductive material so as to form an electrically conductive heating track comprising at least a first heating track section and a second heating track section extending at a distance from each other on the substrate, and an intermediate section of conductive material arranged between the first heating track section and the second heating track section. The width of the intermediate section of conductive material is smaller than the width of a gap between the first heating track section and the second heating track section. The selective removal of the conductive material is performed in such a way that the intermediate section of conductive material is separated from both the first heating track section and the second heating track section, and wherein the selective removal is further performed so as to form a gate member on the surface of the substrate in the gap, wherein the gate member is arranged in a portion of the gap and extends between the layer of conductive material and a single one of the first heating track section and the second heating track section so as to locally connect the layer of conductive material to the one of the first heating track section and the second heating track section.

[0035] The term "middle section" may refer to a layer of conductive material.

[0036] The benefits described in the context of the proposed electrical heating and capacitive sensing arrangement according to the invention fully apply to the proposed further method as well.

[0037] In a preferred embodiment, the step of selectively removing the conductive material is performed by using a cutting process, a laser cutting process, a partial kiss cutting process, a contour cutting process or an etching process, whereby the conductive material is at least partially cut or etched from the outside to the substrate. The term "outside" refers to the side of the conductive material facing the external environment. The cutting process may result in a partial cut, which refers to a cut that removes the material to be cut to a predetermined depth.

[0038] These and other aspects of the invention will be apparent from and elucidated with reference to the embodiments described hereinafter.

[0039] It should be pointed out that the features and measures described individually in the above description can be combined with one another in any technically meaningful manner and represent further embodiments of the invention. The description particularly characterizes and explains the invention in detail in conjunction with the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further details and advantages of the present invention will become apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which:

[0041] Figure 1 A portion of a prior art heating device is schematically shown in a top view;

[0042] Figure 2 Schematically shows the basis Figure 1 A cross section of two adjacent heating lines of a heating device of the prior art, wherein an additional cover is installed;

[0043] Figure 3 schematically illustrates a portion of a top view of an electric heating and capacitive sensing device according to an embodiment;

[0044] Figure 4 Schematically shows Figure 3 a cross-sectional view of an electric heating and capacitive sensing device in which two heating track sections and a layer of conductive material are shown, and in which a trim cover is mounted over the electric heating and capacitive sensing device;

[0045] Figure 5 schematically shows a cross-sectional top view of an electric heating and capacitive sensing device according to another embodiment;

[0046] Figure 6 schematically shows a top view of a steering wheel heater including electric heating and capacitive sensing devices according to an embodiment;

[0047] Figure 7yes Figure 6 An enlarged view of the G segment;

[0048] Figure 8 According to the manufacturing method of the present invention Figures 3 to 6 A flow chart of a method of an electrical heating and capacitive sensing device of any one of the above.

[0049] Fig. 9 According to the manufacturing method of the present invention Figures 3 to 6 A flow chart of another method of an electrical heating and capacitive sensing device of any one of the. DETAILED DESCRIPTION

[0050] Figure 1 is a schematic top view of a prior art heating device 1, wherein the device 1 consists of a plurality of electrically conductive heating wires 2 forming part of a heating track (not shown). The heating wires 2 are electrically connected in parallel. The heating wires 2 are arranged on a supporting substrate 4. The heating and capacitive sensing device also has a plurality of grooves 6, wherein each groove is arranged between two adjacent heating wires 2, thereby exposing the substrate 4. Figure 1 It can be further concluded that the heating wire 2 presents an irregular serpentine shape along a direction parallel to the length direction X of the heating device 1. The inner radius R1 of the serpentine heating wire 2 relative to the inner vertex 7 on the first edge of the heating wire 2 is different from the outer radius R2 relative to the outer vertex 9. The width L1 of the heating wire 2 varies slightly at each point along the heating wire 2. Therefore, during operation of the heating device 1, the heating and capacitive sensing device may easily generate hot spots and / or cold areas.

[0051] Figure 2 yes Figure 1 A schematic sectional view of an electric heating device 1 according to the prior art is shown, wherein two adjacently arranged heating lines 2 are shown. Figure 2 Also shown is a decorative cover 8 of a steering wheel (not shown) mounted on the heating device 1. Figure 2 As can be seen in Figure 1, the absence of material in the grooves 6 between the heating wires 2 causes the cover 8 to extend unevenly over the heating device 1. Therefore, the cover forms bends 10 at the locations where the cover 8 contacts the substrate 4. These bends 10 are perceptible to the user and may also be prone to uneven heat dissipation.

[0052] The heating wire 2 may be used as an antenna for performing capacitive sensing. However, during such capacitive sensing, the groove 6 does not form part of the active area.

[0053] Figure 3 Schematically shows a portion of a top view of an electric heating and capacitive sensing device 100 according to an embodiment, wherein a door member 110 locally connects the conductive layer 103 to the respective adjacent heating track segments 102. In this context, Figure 4 yes Figure 3 Schematic cross-sectional view of an electric heating and capacitive sensing device 100 is shown, wherein two heating track sections 102 and a conductive material layer 103 are shown. It should also be noted that Figure 4 The door member 110 is not shown. Figure 3 The heating track segments 102 shown in the illustrated embodiment may be part of a single heating track, wherein the heating track segments 102 are connected in parallel with each other. The electrically conductive heating track can be connected to a current source (not shown) so that during a heating operation a heating current flows through the electrically conductive heating track and the plurality of heating track segments 102.

[0054] Each heating track segment 102 extends a certain distance along the adjacent heating track segment 102 on the substrate 104, thereby forming and respectively defining a gap 106 between two spaced-apart heating track segments 102. Figure 3 and Figure 4 1 and 2. The substrate 104 is shown by a first heating track 102' and a second heating track segment 102". A conductive material layer 103 is arranged on the surface of the substrate 104 in the gap 106 between the heating track segments 102 (respectively the first heating track segment 102' and the second heating track segment 102". The thickness of the conductive material layer 103 and the thickness of the heating track segments 102 are substantially equal. The substrate 104 comprises a flexible fabric or foil.

[0055] from Figure 4 It can be concluded that the width W1 of the conductive material layer 103 is smaller than the width W2 of the gap 106 between two heating track sections 102. Therefore, the conductive material layer 103 is arranged to be separated from the adjacent heating track sections 102. Figure 3 In other words, a narrow channel-like structure is formed between the edge of the conductive material layer 103 and the corresponding, adjacent heating track sections 102 ′, 102 ″. Therefore, the conductive material layer 103 is separated from the adjacent heating track sections.

[0056] The door member 110 is formed of an electrically conductive material and is arranged in a portion of the gap 106 such that the door member 110 extends between the electrically conductive material layer 103 and an adjacent first heating track segment 102′ or second heating track segment 102″. In other words, the door member 110 is arranged in a narrow channel-like structure formed between an edge of the electrically conductive material layer 103 and an adjacent heating track 102. Thereby, the door member 110 locally connects a single heating track segment to the electrically conductive material layer 103. The door member 110, the layer 103 and the heating tracks are formed of the same material.

[0057] During the heating operation, the heating current flows through the conductive track and the plurality of heating track segments 102. During the capacitive sensing operation, the capacitive sensing signal is applied to the conductive track. Although the heating current may not pass through the door member 110, the capacitive sensing signal is sent during the capacitive sensing operation. Therefore, the conductive material layer 103 expands the sensing area.

[0058] Due to the particularly small difference in widths W1 and W2 and the thermal conductivity of the electrically conductive layer 103, during operation of the heating device 100, heat emitted by adjacent heating track sections 102 can be absorbed by the electrically conductive material layer 103. This allows a particularly uniform heat dissipation to be achieved.

[0059] It should also be noted that each heating track segment may have a width in the range of 2mm to 10mm, preferably in the range of 4mm to 8mm, most preferably 6mm. The wavelength is in the range of 12mm to 18mm, preferably in the range of 14mm to 16mm, most preferably 15mm.

[0060] Figure 4 A decorative cover 108 mounted on an electric heating and capacitive sensing device 100 is shown, wherein the decorative cover 108 is configured for a steering wheel (not shown). The decorative cover 108 is uniformly extended on the heating track segment 102 and the conductive layer 103. The decorative cover 108 may include an insulating material. A portion of the decorative cover 108 protrudes in a channel-like structure between the conductive material layer 103 and the adjacent heating track segment 102 on the surface of the substrate 104. Therefore, the electric heating and capacitive sensing device 100 is not easily perceived by the user or is not perceived by the user at all, and the formation of bending is significantly reduced. In addition, the protruding portion of the decorative cover 108 can also provide electrical isolation between the conductive material layer 103 and the adjacent heating track segment 102 that is not connected to the layer 103 through the door member 110. In an alternative embodiment (not shown), the insulating material can be arranged only on the surface of the substrate 104 between the conductive material layer 103 and the heating track segment.

[0061] Figure 5 FIG. 2 is a schematic top view of an electric heating and capacitive sensing device 200 according to another embodiment of the present invention. Figure 5 In the embodiment shown, the inner radius R1 and the outer radius R2 are equal. Figure 5 The embodiment shown is Figure 3 and Figure 4 It should be noted that the door member is Figure 5 Each heating track section 202 has a wavy shape extending along the length direction X of the electric heating and capacitive sensing device 200. Figure 5In the illustrated embodiment, the first heating track segment 202' has an inner radius R1 relative to an inner vertex 207 at a first edge 212 of the first heating track segment 202'. The inner radius R1 extends over a portion of the first heating track segment 202' to a second edge 214 of the first heating track segment 202'. The first heating track segment 202' also has an outer radius R2 relative to an outer vertex 209 at the second edge 214 of the first heating track segment 202'. The outer radius R2 extends over a portion of the gap 206, respectively, on the conductive material layer 203 arranged in the gap 206, to a first edge 222 of the second heating track segment 202". Both the inner radius R1 and the outer radius R2 may have equal lengths in the range of 2 mm to 10 mm, preferably in the range of 4 mm to 8 mm, and most preferably a length of 6 mm. Moreover, the width L1 of each heating track segment 202 is constant. The width L1 is in the range of 2 mm to 10 mm.

[0062] Figure 6 A further embodiment of an electric heating and capacitive sensing device 300 is shown in a schematic top view, respectively a steering wheel heater comprising electric heating and capacitive sensing devices. Figure 6 The embodiment shown is suitable for installation on a steering wheel (not shown). The electric heating device 300 includes a plurality of sections A, B, C, each of which presents a Figure 5 The structure of the embodiment shown. It can be seen that, for example, in section B, the conductive material layer 303 extends in the gap between adjacent heating track sections 302. The door member 310 ( Figure 6 (not shown) connects each conductive material layer 303 to a single adjacent heating track segment 302. Figure 7 It is shown in Figure 6 Magnified view of the G segment.

[0063] The electric heating and capacitive sensing device 300 includes an electrically conductive heating track 316, which includes a plurality of heating traces 318', 318", 318'", wherein the heating traces are electrically connected to each other. The heating track 316 has a meandering shape at the D section and the F section of the heating device 300. In addition, the heating track has a U-shaped portion in the section E. As shown in FIG. Figure 6 It can be seen that the heating track 316 includes a heating track 318' having a U-shaped portion, which is at least partially formed by a first heating track segment 302' and a second heating track segment 302". The first heating track segment 302' and the second heating track segment 302" both form branches of the U-shape. Due to the meandering shape and the U-shaped portion of the heating track, the electric heating and capacitive sensing device dissipates heat evenly over a particularly large area.

[0064] The electric heating and capacitive sensing device 300, respectively, a steering wheel heater comprising an electric heating and capacitive sensing device, may also have two contact terminals 320, 322. The two contact terminals 320, 322 can be connected to a power source. The contact terminals are arranged at the ends of the conductive heating track 316. The contact terminals may be connected to a control unit (not shown), which is configured to connect the current source to the terminals 320, 322 to control the heating operation accordingly. The control unit may also control and / or process the capacitive sensing operation.

[0065] Figure 8 According to the manufacturing method of the present invention Figure 3-7 A flow chart of a method for an electrical heating and capacitive sensing device of any embodiment shown. Figure 3 and Figure 4 Describe the steps of the method.

[0066] The method of manufacturing an electrical heating and capacitive sensing device 100 comprises the following steps: In one step 80, a planar substrate 104 is provided. In a further step 82, an electrically conductive heating track is applied on the surface of said substrate 104. The electrically conductive heating track comprises at least a first heating track section 102' and a second heating track section 102" extending along a distance W2 from each other on said substrate 104, thereby forming a gap 106 between said first heating track section 102' and said second heating track section 102".

[0067] In a further step 84, a layer of electrically conductive material 103 is applied on the surface of the substrate 104 in the gap 106, wherein a width W1 of the layer of electrically conductive material 103 is smaller than a width W2 of the gap 106 between the first heating track segment 102' and the second heating track segment 102". The layer of electrically conductive material 103 is located on the substrate 104 so as to be separated from the first heating track segment 102' and the second heating track segment 102".

[0068] In a further step 86, a conductive material is applied on the surface of the substrate in the gap so as to form a door member 110, wherein the door member 110 is arranged within a portion of the gap 106 and extends between the conductive material layer 103 and a single one of the first heating track segment 102' and the second heating track segment 102", so as to locally connect the conductive material layer 103 to the one of the first heating track segment 102' and the second heating track segment 102".

[0069] It should be noted that steps 82, 84 and 86 may be performed simultaneously or sequentially. It should also be noted that the order of steps 82, 84 and 86 may be changed.

[0070] Fig. 9 According to the manufacturing method of the present invention Figure 3-6 A flow chart of another method of the electric heating and capacitive sensing device of any embodiment shown. Figure 3 and Figure 4 Describe the steps of the method.

[0071] Another method of manufacturing an electric heating and capacitive sensing device 100 comprises the following steps: In one step 90, a planar substrate 104 is provided. In a further step 92, a layer of electrically conductive material is applied on the surface of the substrate 104. In a further step 94, parts of the electrically conductive material are selectively removed so as to form an electrically conductive heating track comprising at least: a first heating track section 102' and a second heating track section 102" extending at a distance W2 from each other on the substrate 104, and an intermediate section of conductive material 103 arranged between the first heating track section 102' and the second heating track section 102". The width W1 of the intermediate section of conductive material 103 is smaller than the width W2 of a gap 106 between the first heating track section 102' and the second heating track section 102".

[0072] The step 94 of selectively removing the conductive material is performed in such a manner that the middle section 103 of the conductive material is separated from both the first heating track section 102' and the second section heating track section 102". The step 94 of selectively removing the conductive material is further performed so as to form a door member 110 on the surface of the substrate 104 in the gap 106, wherein the door member 110 is arranged in a portion of the gap 106 and extends between the conductive material layer 103 and a single one of the first heating track section 102' and the second heating track section 102" so as to locally connect the conductive material layer 103 to the one of the first heating track section 102' and the second heating track section 102".

[0073] In a preferred embodiment, the step 94 of selectively removing the conductive material 103 is performed by using a cutting process, a laser cutting process, a partial kiss cutting process, a contour cutting process or an etching process, whereby the conductive material is at least partially cut or etched from the outside to the substrate 104 .

[0074] While the invention has been illustrated and described in detail in the drawings and foregoing description, such illustration and description are to be considered illustrative or exemplary and not restrictive; the invention is not limited to the disclosed embodiments.

[0075] Other variations of the disclosed embodiments may be understood and implemented by those skilled in the art in practicing the claimed invention by studying the drawings, the disclosure and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the indefinite article "a" or "an" does not exclude a plurality, and is intended to express a quantity of at least two. The fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage. Any reference signs in the claims should not be interpreted as limiting the scope.

[0076] Reference numerals list

[0077] 1. Prior art heating equipment

[0078] 2 Heating wire

[0079] 4 substrates

[0080] 6 grooves

[0081] 7 Inner Vertex

[0082] 8 hoods

[0083] 9 outer vertices

[0084] 100 Electrical heating and capacitive sensing devices

[0085] 102 Heating track section

[0086] 103 Conductive materials

[0087] 104 substrate

[0088] 106 Gap

[0089] 108 hood

[0090] 110 Door components

[0091] 200 Electric heating and capacitive sensing device

[0092] 202 Heating track section

[0093] 203 Conductive materials

[0094] 206 Gap

[0095] 207 inner vertices

[0096] 209 Outer Vertex

[0097] 300 Electric heating and capacitive sensing device

[0098] 310 door components

[0099] 320 contact terminal

[0100] 322 contact terminal

Claims

1. An electric heating and capacitive sensing device (100; 200; 300), comprising: A planar substrate (104); an electrically conductive heating track (316) arranged on a surface of the substrate (104), the electrically conductive heating track being connectable to a current source such that current flows through the electrically conductive heating track during a heating operation, and the electrically conductive heating track being connectable to a capacitive sensing circuit such that a capacitive sensing signal is applied to the electrically conductive heating track during a sensing operation, wherein the electrically conductive heating track (316) comprises at least a first heating track section (102'; 202'; 302') and a second heating track section (102"; 202"; 302") extending at a distance from each other on the substrate (104), thereby forming a gap (106; 206; 306) between the first heating track section and the second heating track section; Characterized in that the electric heating and capacitive sensing device also includes: a conductive material layer (103; 203; 303) arranged on the surface of the substrate (104) in the gap (106; 206; 306) between the first heating track segment and the second heating track segment; wherein a width (W1) of the conductive material layer (103; 203; 303) is smaller than a width (W2) of the gap (106) between the first heating track segment and the second heating track segment; wherein the conductive material layer (103; 203; 303) is arranged to be separated from the first heating track segment and the second heating track segment; and A door member (110; 310) of conductive material is arranged in a portion of the gap and extends between the conductive material layer and a single one of the first heating track segment and the second heating track segment so as to locally connect the conductive material layer to the one of the first heating track segment and the second heating track segment.

2. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1, wherein: The door member (110; 310), the electrically conductive heating track (316) and / or the electrically conductive material layer (103; 203; 303) are formed from the same electrically conductive material.

3. An electrical heating and capacitive sensing device (100; 200; 300) according to any one of the preceding claims, wherein: The length extension of the door member (110; 310) in the extension direction of the first heating track section and the second heating track section is at least 50 times smaller than the length extension of the conductive material layer in this direction.

4. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 3, wherein: The length extension of the door member (110; 310) is at least 100 times smaller than the length extension of the layer of conductive material.

5. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 4, wherein: The length extension of the door member (110; 310) is at least 200 times smaller than the length extension of the layer of conductive material.

6. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: The thickness of the conductive material layer (103; 203; 303) is substantially equal to the thickness of the first heating track section and / or the second heating track section.

7. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: The substrate (104) comprises a conductive fabric or foil.

8. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: Each of the first heating track segment and the second heating track segment has a first wavy shape extending along a length direction (X) of the electric heating and capacitive sensing device.

9. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 8, wherein: The first heating track segment (202') has an inner radius (R1) relative to an inner vertex (207) at a first edge (212) of the first heating track segment (202'), wherein the inner radius (R1) extends over a portion of the first heating track segment (202') to a second edge (214) of the first heating track segment; and wherein the first heating track segment has an outer radius (R2) relative to an outer vertex (209) at the second edge (214), wherein the outer radius (R2) extends over a portion of the gap (206) to a first edge (222) of the second heating track segment (202"); and wherein the inner radius (R1) and the outer radius (R2) are equal.

10. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: The conductive heating track (316) comprises at least one of the following: Cu, Ni, Ag, Al or a mixture thereof.

11. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: The electrically conductive heating track (316) comprises a plurality of heating traces (318'; 318"; 318"'), wherein a first heating trace of the plurality of heating traces comprises the first heating track segment, and wherein a second heating trace of the plurality of heating traces comprises the second heating track segment.

12. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 1 or 2, wherein: The electrically conductive heating track (316) has a meandering shape, and wherein the first heating track section and the second heating track section are formed by adjacent branches of the meandering shape.

13. The electrical heating and capacitive sensing device (100; 200; 300) according to claim 12, wherein: The zigzag shape is a U shape.

14. A steering wheel heater (300) for automotive applications, comprising an electric heating and capacitive sensing device (100; 200; 300) according to any one of claims 1 to 10, the steering wheel heater further comprising: The current source, which can be connected to the contact terminals (320; 322) of the electrically conductive heating track (316); a control unit configured to connect the current source to the terminal to control the heating operation accordingly; and the capacitive sensing circuit for transmitting the capacitive sensing signal.

15. A method of manufacturing an electrical heating and capacitive sensing device, the method comprising at least the following steps: providing a planar substrate; applying an electrically conductive heating track on a surface of the substrate, the electrically conductive heating track comprising at least a first heating track section and a second heating track section, the first heating track section and the second heating track section extending at a distance from each other on the substrate, thereby forming a gap between the first heating track section and the second heating track section; applying a layer of conductive material on the surface of the substrate in the gap; wherein the width of the conductive material layer is less than the width of the gap between the first heating track segment and the second heating track segment; and wherein the conductive material layer is located on the substrate so as to be separated from the first heating track segment and the second heating track segment; A conductive material is applied to form a gate member on the surface of the substrate in the gap, the gate member being arranged within a portion of the gap and extending between the conductive material layer and a single one of the first heating track segment and the second heating track segment so as to locally connect the conductive material layer to the one of the first heating track segment and the second heating track segment.

16. A method of manufacturing an electrical heating and capacitive sensing device, the method comprising at least the following steps: providing a planar substrate; applying a layer of conductive material on a surface of the substrate; selectively removing portions of the conductive material to form a conductive heating track, the conductive heating track comprising at least a first heating track segment and a second heating track segment extending at a distance from each other on the substrate, and an intermediate segment of conductive material arranged between the first heating track segment and the second heating track segment; wherein a width of the intermediate segment of conductive material is smaller than a width of a gap between the first heating track segment and the second heating track segment; and wherein said selective removal of the conductive material is performed in such a way that said intermediate section of conductive material is separated from both said first heating track section and said second heating track section, And wherein the selective removal is further performed so as to form a gate member on the surface of the substrate in the gap, the gate member being arranged within a portion of the gap and extending between the conductive material layer and a single one of the first heating track segment and the second heating track segment so as to locally connect the conductive material layer to the one of the first heating track segment and the second heating track segment.

17. The method according to claim 16, wherein: The step of selectively removing the conductive material is performed by using a cutting process, a laser cutting process, a partial kiss cutting process, a contour cutting process or an etching process, whereby the conductive material is at least partially cut or etched from the outside to the substrate.

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