Contactless inductive multichannel rotation angle sensor

Abstract

The present invention relates to a contactless inductive multi-channel rotation angle sensor having two channels, a stator (S) and a rotor (R), wherein the stator (S) has: a circuit board (2) having at least a first layer (21), a second layer (22) and a third layer (23); a transmitting coil for each channel; and at least three receiving coils for each channel; and at least one electronic circuit for each channel for generating a transmitting signal to be emitted through the transmitting coil and / or for analyzing a receiving signal to be received through the receiving coil.

Description

Technical Field

[0001] This invention relates to a contactless, inductive, multi-channel rotation angle sensor, which has a pair of channels, a stator, and a rotor.

[0002] The stator has the following characteristics:

[0003] - A circuit board having at least a first layer, a second layer, and a third layer.

[0004] - Each channel has one transmitting coil.

[0005] - At least two receiving coils per channel, and

[0006] - Each channel has at least one electronic circuit for generating a transmit signal to be emitted through the transmit coil and / or for analyzing a receive signal to be received through the receive coil.

[0007] in,

[0008] The first layer has a conductive structure, particularly a copper structure; the second layer is a layer made of an insulator; and the third layer has a conductive structure, particularly a copper structure.

[0009] - The receiving coils of each channel are configured as conductive structures in the first and third layers of the circuit board, which are separated from each other by a second layer made of an insulator.

[0010] - The electronic circuitry is mounted on a circuit board, and

[0011] The rotor has a closed conductor circuit. Background Technology

[0012] Such a contactless, inductive, two-channel rotation angle sensor is known from document EP 0 900 997B1. The sensor technology disclosed in that document is used in motor vehicles, specifically in accelerator pedals and in steering angle and rotation angle sensors, which are used, for example, in motor controllers. This contactless, inductive rotation angle sensor is known from document DE 10 2004 027 954 B4 as a further extension of sensors for measuring torsional angles, using which torque can be detected.

[0013] The ever-increasing safety requirements for automotive electronics have also raised the demands on sensors in terms of error identification, avoidance, and response. Thus, in x-by-wire systems, it becomes unreliable, for example, for sensors to shut down due to simple errors such as voltage supply failures. For this reason, two identical sensors are redundantly used, supplied by different onboard electrical networks or batteries and connected to different controllers. To further ensure high signal integrity (up to ASIL D for erroneous signals according to ISO 26262), synchronous monitoring between the at least two sensors is also required. For synchronous monitoring, each of the two sensors is connected to two controllers, which redundantly perform synchronous monitoring. Because signal paths on different controllers lead to excessive signal alteration, it is desirable that each controller also utilizes at least two sensors, increasing the number of sensors to at least four. The problem now to be solved is to functionally, cost-effectively, and with high performance integrate these four sensors into a single system.

[0014] Besides the contactless, inductive rotation angle sensors of the type described at the beginning, Hall sensors are known in which two sensor channels (each on a chip) are built / combined in an ASIC. These sensor channels are typically stacked side-by-side or vertically, spaced apart by a small distance. When using more than two channels, a new ASIC must be developed, or one ASIC must be placed on the circuit board while another is placed underneath. This results in excessively high differences in the air gap between the magnet and the Hall-sensitive surface, leading to problems in signal processing (signal strength and sensor error). Furthermore, the two ASICs, or their Hall-sensitive surfaces, are not simultaneously positioned sufficiently close to the axis of rotation on the side of the circuit board, thus also increasing sensor error, rendering the sensor unusable for accuracy requirements. Therefore, Hall sensors appear unsuitable for the development of functional, cost-effective, and high-performance integrated systems. Summary of the Invention

[0015] Therefore, the inventor proposed the following task: to develop a multi-channel rotation angle sensor based on the contactless inductive rotation angle sensor described at the beginning.

[0016] According to the present invention, the task is achieved by the following: the multi-channel rotation angle sensor has at least two additional channels, wherein the stator has

[0017] - Each of the other channels has a separate transmitting coil.

[0018] - Each additional channel has at least two receiving coils.

[0019] - Each additional channel has at least one additional electronic circuit for generating a transmit signal to be emitted by the transmit coil of said additional channel and / or for analyzing a receive signal to be received by the receive coil of said additional channel.

[0020] in,

[0021] - The circuit board has at least an additional first layer, an additional second layer, and an additional third layer for the two additional channels.

[0022] - The additional first layer has a conductive structure, particularly a copper structure; the additional second layer is a layer made of an insulator; and the additional third layer has a conductive structure, particularly a copper structure.

[0023] The receiving coil of the additional channel is configured as a conductive structure in the additional first layer and the additional third layer of the circuit board, the additional first layer and the additional third layer being separated from each other by the additional second layer made of an insulator.

[0024] - The additional electronic circuitry is mounted on the circuit board.

[0025] By utilizing this additional channel, a total of four sensors, or channels, can be functionally, cost-effectively, and with high performance integrated into a single system. The multi-channel rotation angle sensor according to the invention can also have more than one additional channel, for example, two to five additional channels, thus the multi-channel rotation angle sensor according to the invention can, for example, have up to twelve channels. The circuit board arrangement allows the layers for different pairs of additional channels to be laid flat and overlapping each other, wherein two adjacent layers of different pairs having conductive structures are separated from each other by a layer made of an insulator. Here, the additional first layers of different pairs are adjacent and separated from each other by a layer made of an insulator. However, it is also possible that the additional first layers and the additional third layers of different pairs are adjacent and separated from each other by a layer made of an insulator.

[0026] The transmitting coil of the channel can

[0027] It is configured as a conductive structure in the first or third layer, or

[0028] The conductive structure is configured as a fifth layer in the circuit board, which is separated from the third layer by a fourth layer made of an insulator, or

[0029] - It is configured as a conductive structure in the fifth and seventh layers of the circuit board, wherein the fifth layer is separated from the third layer by the fourth layer of the circuit board made of an insulator, and the seventh layer is separated from the fifth layer by the sixth layer of the circuit board made of an insulator.

[0030] Accordingly, the transmitting coil of the other channel can

[0031] The conductive structure is configured in the additional first layer or the additional third layer, or

[0032] This is configured as a conductive structure in the fifth layer of a circuit board, which is separated from the third layer by an additional fourth layer made of an insulator, or...

[0033] It is configured as a conductive structure in the fifth and seventh layers of the circuit board, wherein the seventh layer is separated from the third layer by another fourth layer made of an insulator on the circuit board.

[0034] The conductive structure of the transmitting coil for the aforementioned channel can therefore be constructed together with the conductive structure of the transmitting coil for the other channel on the fifth layer, or on both the fifth and seventh layers. Alternatively, the transmitting coils can be disposed on different layers.

[0035] The conductive structures of the first and third layers can be interconnected via microvias in the second layer, and the conductive structures of the additional first and third layers can be interconnected via microvias in the additional second layer. These microvias are redundantly, and in particular, dually implemented to improve fault tolerance.

[0036] Furthermore, the electronic circuitry can be connected to the conductive structure forming the transmitting coil in the third, fifth, or seventh layer via microvias, and the additional electronic circuitry can be connected to another conductive structure forming another transmitting coil in the third, fifth, or seventh layer via microvias. These microvias can also be redundantly, particularly in a dual manner, to improve fault tolerance.

[0037] The application of microvias (which can also refer to embedded microvias) is particularly advantageous for separating transmitting and receiving coils, because otherwise, a high number of via metallization would make line routing on the corresponding layer or another layer with conductive structures extremely difficult and would compromise the symmetry of the circuit board. Moreover, the use of microvias precisely limits the number of possible short circuits between different receiving and transmitting coils in an n-channel sensor (n>2), because short circuits may occur in a limited number of locations on the circuit board and the channels or sensors can be spatially separated from each other, thus eliminating the possibility of some short circuits.

[0038] The circuit board of the multi-channel rotation angle sensor according to the present invention can have a thickness of 1 mm or more. Sufficient strength of the circuit board is ensured even with a thickness of 1 mm. Otherwise, there is an increased risk of damage due to mechanical influences (e.g., assembly forces).

[0039] Preferably, the layers of the circuit board are arranged symmetrically about a plane between the front and rear sides of the circuit board. This prevents bending under temperature influence. To achieve symmetry, or the best possible symmetry, the second layer and the second layer have the same thickness, more specifically, preferably 300 to 400 µm. Similarly, for the same reason, the fourth layer and the second layer have the same thickness, more specifically, also preferably 300 to 400 µm.

[0040] In the multi-channel rotation angle sensor according to the present invention, the transmitting and receiving coils of different channels have different distances from the rotor. Because the electric field strength decreases with distance from the rotor, a problem arises where the receiving coil closer to the rotor receives a signal with a higher signal strength than the receiving coil farther from the rotor. Since typical sensors shut down not only when the signal strength is too low but also when the signal strength is too high, it is meaningful to adapt the diameter of the receiving coils so that the signal strength of the received signals is within the same range. Otherwise, each channel would respond differently to external influences, which negatively impacts the overall performance of the multi-channel rotation angle sensor.

[0041] However, the variation in signal strength between signals received by different channels is much smaller compared to solutions where, for example, Hall sensors are placed on both sides of a circuit board, due to the much lower distance. The distance between Hall sensors can be approximately 2 to 3 mm in the aforementioned case, while it is <1 mm in the inductive solution shown. Moreover, the Hall sensor-based solution is currently limited to a 4-channel sensor in its configuration. The solution according to the invention is essentially limited by the minimum thickness of the layers made of insulators, which is determined by manufacturing, so a multi-channel rotation angle sensor according to the invention with six to twelve channels could also be created based on this.

[0042] According to the present invention, the electronic circuitry for the receiving coil near the rotor can be placed on the side facing the rotor, and the electronic circuitry for the receiving coil away from the rotor can be placed on the side of the circuit board away from the rotor. This minimizes short circuits between the various electronic circuits. Attached Figure Description

[0043] The multi-channel rotation angle sensor according to the present invention has a four-channel structure, which is described with reference to the accompanying drawings. In the drawings:

[0044] Figure 1 A side view of a multi-channel sensor is shown schematically. Detailed Implementation

[0045] The schematic diagram shows a rotor R and a stator S. The rotor R includes a closed conductor loop. The stator includes a circuit board 2 and electronic circuits 1, 1' disposed on the front and rear sides, the electronic circuits including resistors, diodes, capacitors and / or ICs, such as FPGAs, ASICs or other ICs.

[0046] Circuit board 2 is a multilayer circuit board, which includes layers made of insulator and layers having conductive structures, preferably copper structures. Specifically, from front to back, the circuit board consists of a first layer 21 with a copper structure, a second layer 22 made of insulator, a third layer 23 with a copper structure, a fourth layer 24 made of insulator, a fifth layer 25 with a copper structure, a sixth layer 26 made of insulator, a seventh layer 27 with a copper structure, another fourth layer 24' made of insulator, another third layer 23' with a copper structure, another second layer 22' made of insulator, and another first layer 21' with a copper structure.

[0047] The copper structures of the first layer 21 and the third layer 23, or the additional first layer 21' and the additional third layer 23', are interconnected through microvias to form receiving coils, more specifically, three for each of the four channels. Here, six receiving coils for two channels in each channel are formed in the first layer 21 and the third layer 23, and six receiving coils for the two additional channels in each channel are formed in the additional first layer 21' and the additional third layer 23'.

[0048] The electronic circuit is electrically connected to the receiving coil. More specifically, the electronic circuit 1 on the front side is electrically connected to the receiving coil in the first layer 21 and the third layer 23, and the additional electronic circuit on the rear side of the circuit board 2 is electrically connected to the receiving coil in the additional first layer 21' and the additional third layer 23'.

[0049] A copper structure is provided in the fifth layer 25, forming a transmitting coil for one of the two channels, along with receiving coils in the first layer 21 and the third layer 23. A copper structure is provided in the seventh layer 27, forming a transmitting coil for the other of the two channels, along with receiving coils in the first layer 21 and the third layer 23. The two receiving coils are connected to electronic circuitry 1 on the front side of the circuit board 2 via microvias.

[0050] Furthermore, a copper structure is provided in the fifth layer 25, which forms a transmitting coil for one of the two channels, along with receiving coils in another first layer 21' and another third layer 23'. A copper structure is provided in the seventh layer 27, which forms a transmitting coil for the other of the two channels, along with receiving coils in another first layer 21' and another third layer 23'. The two receiving coils are connected via microvias to additional electronic circuitry 1' on the front side of the circuit board 2.

[0051] An electromagnetic field is generated by a transmitting coil, causing the rotor to move within this field. This induces a current in a closed conductive loop, which is altered, and particularly weakened, by the field generated by the transmitting coil. This alteration changes the current passing through the receiving coil, which is detected by electronic circuits 1, 1'. The rotor's position relative to the stator can thus be detected using each of the four channels of the multi-channel sensor in a known manner. The electronic circuits are independent of each other and interface with each controller, which is powered by different batteries in the vehicle.

[0052] List of reference numerals

[0053] S stator

[0054] R rotor

[0055] 1 Electronic Circuits

[0056] 1' Other electronic circuits

[0057] 2 circuit boards

[0058] 21. First layer (with copper structure)

[0059] 22 Second layer (insulator)

[0060] 23. Third layer (with copper structure)

[0061] 24. Fourth layer (insulator)

[0062] 25. Fifth layer (with copper structure)

[0063] 26. Sixth layer (insulator)

[0064] 27. Seventh layer (with copper structure)

[0065] 21' Another first layer (with copper structure)

[0066] 22' The additional second layer (insulator)

[0067] 23' An additional third layer (with a copper structure)

[0068] 24' An additional fourth layer (insulator)

Claims

1. Non-contact, inductive, multi-channel rotation angle sensor - Has two channels, - It has a stator (S) and a rotor (R). in, The stator (S) has - Circuit board (2), the circuit board having at least a first layer (21), a second layer (22) and a third layer (23). - One transmitting coil for each channel and - At least two receiving coils per channel - Each channel has at least one electronic circuit for generating a transmit signal to be emitted through the transmit coil and / or for analyzing a receive signal to be received through the receive coil. in, The first layer (21) has a conductive structure, the second layer (22) is a layer made of an insulator, and the third layer (23) has a conductive structure. The receiving coils of the channel are configured as conductive structures in the first layer (21) and the third layer (23) of the circuit board (2), which are separated from each other by a second layer (22) made of an insulator. The electronic circuit (1) is mounted on the circuit board (2), and The rotor (R) has a closed conductor circuit. Its features are, The multi-channel rotation angle sensor has at least two additional channels, wherein the stator (S) has: - Each of the other channels has its own transmitting coil. - Each additional channel has at least two receiving coils. - Each additional channel has at least one additional electronic circuit (1') for generating a transmit signal to be emitted by the transmit coil of said additional channel and / or for analyzing a receive signal to be received by the receive coil of said additional channel. in, The circuit board (2) has at least an additional first layer (21'), an additional second layer (22') and an additional third layer (23') for the two additional channels. The additional first layer (21') has a conductive structure, the additional second layer (22') is a layer made of an insulator, and the additional third layer (23') has a conductive structure. The receiving coil of the additional channel is configured as a conductive structure in the additional first layer (21') and the additional third layer (23') of the circuit board (2), the additional first layer and the additional third layer being separated from each other by the additional second layer (22') made of an insulator. The additional electronic circuit (1') is disposed on the circuit board (2).

2. The contactless, inductive, multi-channel rotation angle sensor according to claim 1, characterized in that, The transmitting coil of the channel It is configured as a conductive structure in the first layer (21) or the third layer (23), or The conductive structure is configured in the fifth layer (25) of the circuit board (2), which is separated from the third layer (23) by a fourth layer (24) made of an insulator, or The conductive structure is configured in the fifth layer (25) and the seventh layer (27) of the circuit board (2), wherein the fifth layer (25) is separated from the third layer (23) by the fourth layer (24) of the circuit board (2) made of an insulator, and the seventh layer (27) is separated from the fifth layer (25) by the sixth layer (26) of the circuit board (2) made of an insulator.

3. The contactless, inductive, multi-channel rotation angle sensor according to claim 1, characterized in that, The transmitting coil of the other channel It is configured as a conductive structure in another first layer (21') or another third layer (23'), or The conductive structure is configured in the fifth layer (25) of the circuit board, which is separated from the other third layer (23') by an additional fourth layer (24') made of an insulator, or The conductive structure is configured in the fifth layer (25) and the seventh layer (27) of the circuit board, wherein the seventh layer (27) is separated from the other third layer (23') by another fourth layer (24') of the circuit board made of an insulator.

4. The contactless, inductive, multi-channel rotation angle sensor according to claim 2, characterized in that, The transmitting coil of the other channel It is configured as a conductive structure in another first layer (21') or another third layer (23'), or The conductive structure is configured in the fifth layer (25) of the circuit board, which is separated from the other third layer (23') by an additional fourth layer (24') made of an insulator, or The conductive structure is configured in the fifth layer (25) and the seventh layer (27) of the circuit board, wherein the seventh layer (27) is separated from the other third layer (23') by another fourth layer (24') of the circuit board made of an insulator.

5. The contactless, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The conductive structure is a copper structure.

6. The non-contact, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The conductive structures of the first layer (21) and the third layer (23) are interconnected through micropores in the second layer (22), and the conductive structures of the other first layer (21') and the other third layer (23') are interconnected through micropores in the other second layer (22').

7. The contactless, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The electronic circuit (1) is connected to the conductive structure of the third layer (23), the fifth layer (25) or the seventh layer (27) forming the transmitting coil through a micropore, and the additional electronic circuit (1') is connected to the conductive structure of the transmitting coil of the other third layer (23'), the fifth layer (25') or the seventh layer (27') forming another channel through a micropore.

8. The contactless, inductive, multi-channel rotation angle sensor according to claim 6, characterized in that, The micropores are implemented in a dual manner.

9. The contactless, inductive, multi-channel rotation angle sensor according to claim 6, characterized in that, Some of the micropores are implemented as dual pores.

10. The contactless, inductive, multi-channel rotation angle sensor according to claim 7, characterized in that, The micropores are implemented in a dual manner.

11. The contactless, inductive, multi-channel rotation angle sensor according to claim 7, characterized in that, Some of the micropores are implemented as dual pores.

12. The contactless, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The circuit board has a thickness of 1 mm or more.

13. The contactless, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The layers of the circuit board (2) are arranged symmetrically about the plane between the front and rear sides of the circuit board (2).

14. The contactless, inductive, multi-channel rotation angle sensor according to any one of claims 1 to 4, characterized in that, The second layer (22) and the other second layer (22') have the same thickness.

15. The contactless, inductive, multi-channel rotation angle sensor according to claim 14, characterized in that, The thickness of the second layer (22) and the additional second layer (22') is 300 to 400 µm.

16. The contactless, inductive, multi-channel rotation angle sensor according to claim 4, characterized in that, The fourth layer (24) and the other fourth layer (24') have the same thickness.

17. The contactless, inductive, multi-channel rotation angle sensor according to claim 4, characterized in that, The thickness of the fourth layer (24) and the additional fourth layer (24') is 300 to 400 µm.

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