阅读说明：本技术 传感器封装 (Sensor package ) 是由 V·伊犁格斯曼 W·克鲁格 D·伊莱 J·陈 J·吕迪格 S·拜尔 于 2019-01-22 设计创作，主要内容包括：描述了一种传感器封装(100),包括：非导电衬底(105)；位于非导电衬底(105)的第一侧(115)处的至少两个导电线圈(110a-c),位于非导电衬底(105)的、与该非导电衬底(105)的第一侧相对的第二侧(125)处的评估电路(120),以及至少两个导电线圈(110a-c)与评估电路(120)之间的导电连接件。(It is described a sensor package (100) comprising: a non-conductive substrate (105); at least two conductive coils (110a-c) located at a first side (115) of a non-conductive substrate (105), an evaluation circuit (120) located at a second side (125) of the non-conductive substrate (105) opposite the first side of the non-conductive substrate (105), and a conductive connection between the at least two conductive coils (110a-c) and the evaluation circuit (120).)

1. A sensor package (100) comprising:

a non-conductive substrate (105);

at least two conductive coils (110a-c) located at a first side (115) of the non-conductive substrate (105);

an evaluation circuit (120) located at a second side (125) of the non-conductive substrate (105) opposite the first side (115) of the non-conductive substrate (105); and

an electrically conductive connection between the at least two electrically conductive coils (110a-c) and the evaluation circuit (120).

2. The sensor package (100) of claim 1, wherein the substrate (105) comprises an electrically insulating, non-metallic, and/or low dielectric loss material.

3. The sensor package (100) according to any one of the preceding claims, wherein the substrate (105) is configured for imparting substantial structural rigidity, or wherein a lead frame is configured for imparting structural rigidity.

4. The sensor package (100) according to any one of the preceding claims, wherein the substrate (100) comprises connection pads (130), the connection pads (130) being on the second side of the substrate (105) for connecting the at least two electrically conductive coils (110a-c) with the evaluation circuit (120).

5. The sensor package (100) according to any one of the preceding claims, wherein the evaluation circuit (120) is mounted as a flip chip on the second side (125) of the substrate (105).

6. The sensor package (100) according to any one of the preceding claims, wherein the at least two electrically conductive coils (110a-c) are at least partially integrated into the substrate (105) on the first side (115) of the substrate (105).

7. The sensor package (100) according to any one of the preceding claims, wherein the at least two electrically conductive coils (110a-c) do not structurally overlap each other, or at least partially structurally overlap each other.

8. The sensor package (100) of any one of the preceding claims, wherein one of the at least two conductive coils (110a-c) generates a magnetic field and the other of the at least two conductive coils (110a-c) receives the magnetic field.

9. The sensor package (100) of any one of the preceding claims, wherein the evaluation circuit (120) is a semiconductor device.

10. The sensor package (100) according to any one of the preceding claims, further comprising:

a lead frame arranged only on the second side (125) of the substrate (105).

11. The sensor package (100) according to claim 10, wherein the evaluation circuit (120) is connected to the lead frame by wire bonding or mounted as a flip chip on the lead frame, or wherein the evaluation circuit (120) is connected to the lead frame via the substrate.

12. The sensor package (100) according to any one of the preceding claims, wherein the at least two conductive coils (110a-c) on the first side (115) of the substrate (105) define a first area, and wherein the evaluation circuit (120) is arranged within a second area on the second side (125) of the substrate (105), the second area being directly opposite to the first area.

13. The sensor package (100) according to any one of the preceding claims, further comprising:

at least one terminal, wherein the at least one terminal is one of a supply terminal (135), an input terminal (140) and an output terminal (145a-n), wherein the at least one terminal is connected to the evaluation circuit (120) and/or to at least one of the at least two conductive coils (110 a-c).

14. The sensor package (100) according to any one of the preceding claims, further comprising:

at least one passive component (150 a-d).

15. The sensor package (100) of any one of the preceding claims, wherein the sensor package (100) is encapsulated by a mold material (155).

Technical Field

The present application relates to sensor packages, and more particularly, to inductive sensor packages for rotational and/or linear position sensing.

Background

Devices for measuring magnetic field properties of a magnetic field are generally referred to as magnetic field sensors or magnetic sensors. Typically, these sensors comprise a sensor element configured for sensing a property of a magnetic field. For example, a hall element, an inductive element such as a coil, or a magnetoresistive element. These sensor elements may also be referred to as magnetic field sensitive elements or sensing elements.

The sensor element is influenced by the magnetic field and outputs a signal indicative of the sensed magnetic field. Thus, direct or indirect measurements may be used. For direct measurement, for example, the magnetic field strength of the magnetic field encountered may be measured, while for indirect measurement, the magnetic flux may be measured by measuring a quantifiable property induced by the magnetic flux (e.g., an induced current or voltage).

However, other elements of the sensor (i.e., non-sensing elements) are also affected by the magnetic field. For example, the magnetic field may induce eddy currents in other elements of the sensor, such as conductive elements (which electrically connect elements of the sensor), and may thus affect the performance of integrated circuits included within the magnetic sensor. Integrated circuits typically perform the task of computing the output of a sensor, and any impact on the operation of the integrated circuit can affect the performance and accuracy of the sensor. The known sensor comprises a lead frame for routing the different elements of the sensor, and on which an integrated circuit is mounted. Such lead frames are susceptible to the generation of eddy currents. For example, if the magnetic field to be sensed by the sensor changes over time, eddy currents are induced in the lead frame, since the lead frame is made of an electrically conductive material. These eddy currents create opposing magnetic fields that affect the accuracy of the sensor, for example, by interfering not only with the operation of the integrated circuit but also with the operation of the sensing element. Thus, these sensors are optimized for sensing static magnetic fields and are subject to high frequency changes of the magnetic field. Thus, it can be said that these sensors are not robust to alternating magnetic fields. Therefore, there is a need for a sensor with reduced eddy current generation.

Existing solutions focus on modifying the effects of eddy currents or on shielding the integrated circuit from eddy currents. An example of an impact reduction concept is given in US6,853,178B 2, where slots are introduced into the lead frame, which are configured to break eddy currents in the lead frame. However, even though the slots introduced into the lead frame may reduce eddy current flow, the magnitude of the eddy current is not changed, and thus the eddy current will still have a significant impact on sensor accuracy.

An example of a shielding concept is described in US 8,629,539B 2. In this case, non-conductive paddles are placed on the lead frame and the integrated circuit. This shielding concept reduces eddy currents for the integrated circuit and not for other components in the surroundings. Furthermore, the non-conductive blades located within the semiconductor material increase the complexity of the sensor, which makes the manufacturing process more difficult.

It is therefore an object of the present application to overcome the drawbacks of the known prior art and to provide an improved sensor package which effectively increases the accuracy of the sensor and provides a compact sensor design, in particular a sensor design wherein the sensing device can be positioned very close to the magnetic field generating or influencing the object.

Disclosure of Invention

The aforementioned object is solved by a sensor package according to the independent claims of the present application.

The sensor package according to the invention may also be referred to as a sensor or an inductive sensor. A sensor package in the sense of the present application is an assembly of sensor elements. The sensor package according to the invention comprises: the sensing device includes a non-conductive substrate, at least two sensing elements located at a first side of the non-conductive substrate, at least one non-sensing element located at a second side of the non-conductive substrate opposite the first side of the non-conductive substrate, and a conductive connection between the at least two sensing elements and the at least one non-sensing element.

Due to the arrangement of the sensing elements, the non-conductive substrate, and the non-sensing elements, the accuracy of the sensor is increased, as fewer sensor elements are exposed to the magnetic field. Thus, less eddy currents are generated that may reduce the accuracy of sensing. In particular, at least two sensing elements are located at a first side of the non-conductive substrate, while at least one non-sensing element is located at a second side. Thus, the at least two sensing elements need not be directly connected to the substrate, but are only physically located on the first side of the substrate. The at least one non-sensing element also need not be directly connected to the substrate, but rather is only physically located on the second side of the substrate. Thus, it can be said that the substrate is located between the at least two sensing elements and the at least one non-sensing element. Thus, one or several further layers in addition to the substrate may be located between the at least two sensing elements and the at least one non-sensing element. These other layers may also be incorporated in the substrate or may be located on one or both sides of the substrate. Thus, also these layers may be located between at least two sensing elements and at least one non-sensing element. These layers may carry various further conductive or non-conductive structures. Alternatively, the different layers themselves may be conductive or non-conductive, for example to provide electrical connections between elements of the sensor package or to isolate them from each other.

The conductive connections between the at least two sensing elements and the at least one non-sensing element may be located only partially on the first side of the substrate to minimize their exposure to the magnetic field so that less eddy currents are induced, which may impart accuracy to the measurement. The conductive connection may thus pass directly from the at least two sensing elements to the at least one non-sensing element, or may pass indirectly from the at least two sensing elements to the at least one non-sensing element. In the case where they pass indirectly from at least two sensing elements to at least one non-sensing element, the conductive connections may be formed by passing through further sensing or non-sensing elements (e.g., further active and/or passive electronic elements). The conductive connections may also be formed by different conductive layers or conductive structures located within a non-conductive substrate.

The non-conductive substrate serves as a central base at which the different sensor elements (i.e. sensing elements) as well as the non-sensing elements are located. By using the non-conductive central pedestal, the generation of eddy currents is reduced. The term non-conductive substrate refers to the portion of the sensor package that serves as the base of the package. The different elements comprised in the sensor package may be assembled on a non-conductive substrate. The substrate may be a solid substrate configured to include or support the different elements of the sensor package. The substrate is a non-conductive substrate, which means that it does not conduct current. Preferably, a glass-reinforced epoxy resin laminate sheet may be used as the substrate material. Glass reinforced epoxy laminates are composite materials comprising woven glass fibers and an epoxy binder, which are flame retardant. However, the substrate may also be formed using ceramic, silicon dioxide, aluminum oxide, sapphire, germanium, gallium arsenide, or an alloy of silicon and germanium.

The non-conductive substrate includes at least a first side and a second side, wherein the first side and the second side are opposite to each other. The side of the substrate may define a surface of the substrate. However, according to the present invention, a side may refer not only to a surface of a substrate having a certain size defined by its length and width. The sides may also define a volume of the substrate that has not only a certain length and width, but also a thickness or height. The first side and the second side of the substrate may have the same thickness. However, it may be possible that the first side and the second side may have different thicknesses. The substrate may comprise a homogeneous material or may comprise a layer structure, wherein the first side of the substrate may comprise at least one layer of the substrate, and wherein the second side of the substrate may comprise at least one other layer of the substrate. The first and second sides of the substrate may be in contact with each other, or they may be separated by a layer that does not belong to either the first or second side of the substrate.

A sensor package according to the present invention may be configured to be sensitive to magnetic fields. The conductive coil is an element of the sensor package and may be referred to as a sensing element. In particular, the conductive coil is an inductive element configured for generating or for receiving a magnetic field. For example, the coil may be a wire, a wire in a coil shape, a wire in a spiral shape, or a wire in a spiral, loop, multi-turn loop, solenoid, inductor, or array shape. The coil is electrically conductive such that it is configured to conduct an electrical current. At least two conductive coils may be arranged on the surface of the substrate, for example by printing, etching, soldering, or gluing the conductive coils on the surface of the first side of the non-conductive substrate. However, it is also possible to integrate at least two electrically conductive coils at least partially into the first side of the substrate. It is also possible to arrange at least two electrically conductive coils on the first side of the substrate at different heights. For example, one of the at least two electrically conductive coils may be arranged at a surface of the first side of the substrate, while the other of the at least two electrically conductive coils is arranged inside the first side of the substrate, thereby being at least partially located below the other electrically conductive coil. Thereby, it is possible that at least two electrically conductive coils at least partially overlap each other. Furthermore, it may also be possible to arrange at least part of the at least two electrically conductive coils on a surface of the first side of the substrate and to arrange the remaining part of the at least two electrically conductive coils inside the first side of the substrate. For example, the at least two electrically conductive coils may have a spiral shape with a certain height. The spiral may start at the surface of the substrate and in particular extend within the first side of the substrate. Thus, the surface of the substrate does not necessarily refer to the uppermost layer or element. According to the present invention, further devices or layers may be present on the surface of the substrate.

For example, the surface may be at least partially coated with a protective layer. For example, if another conductor should be positioned above the conductive coils, at least the portions of the coils where the conductor will cross these coils may be applied with a dielectric so that conductor crossing is possible. Furthermore, a protective layer may be arranged above the at least two electrically conductive coils, which protective layer completely covers the electrically conductive coils.

At least one of the at least two conductive coils may form a sensor element of a sensor package, which sensor element may be sensitive to magnetic fieldsIs effective for treating allergy. This means that at least one of the at least two electrically conductive coils may be configured to receive a magnetic field. The at least one coil may be referred to as a receive coil. The magnetic field may be a vector field, denoted B, which may comprise three components B in a cartesian coordinate system_x、B_yAnd B_z. However, a person skilled in the art will recognize that other components depending only on the definition of the coordinate system are also possible. When at least one of the at least two electrically conductive coils receives a magnetic field, an electrical current may be induced in the at least one coil as described by faraday's law of induction. Further, the current may also be associated with a voltage that may be sensed. The current may be referred to as an induced current, and the voltage may be referred to as an induced voltage. Sensing the induced current or induced voltage may include any of: the device may be configured to record the induced current and/or voltage, measure the induced current and/or voltage, and/or direct the induced current and/or voltage to a device for recording the induced current and/or voltage or a device for measuring the induced current and/or voltage. Such induced current or voltage may also be referred to as a direct sensing signal or a direct measurement signal of the sensor. Further, the at least one receive coil may be configured to communicate with the evaluation circuit. For example, the at least one coil may provide an induced current or voltage or a signal indicative thereof to the evaluation circuit. It may be possible that the evaluation circuit comprises means for registering the induced current and/or the voltage and/or means for measuring the induced current and/or the voltage. The evaluation circuit may then process the induced current and/or voltage and may generate an indirect measurement signal of the sensor.

Further, at least one of the at least two electrically conductive coils may be configured to provide a magnetic field. Providing a magnetic field may also be referred to as generating, or generating a magnetic field. The at least one coil may thus also be referred to as a providing coil, a generating coil, or a transmitting coil. The at least one transmit coil may provide a magnetic field in response to a current that may be applied to the transmit coil and thereby may flow through the transmit coil. The current may cause movement of an electromagnetic charge. As is known in the art, the movement of electromagnetic charges may cause the generation of a magnetic field. This effect is expressed by ampere's law. The strength of the magnetic field, and thus the magnetic flux, is proportional to the amount of current supplied to the coil. The current that can be applied to the at least one transmitting coil can be provided to the at least one transmitting coil by an evaluation circuit. However, it is also possible that the evaluation circuit controls the current or voltage supplied to the at least one transmitting coil. Thus, the transmit coil may also be configured to communicate with the evaluation circuit. However, the current may also be supplied directly to the transmitting coil.

Thus, the sensing element may be formed by an element generating or transmitting a magnetic field, such as a transmitting coil, and by an element sensing or measuring a magnetic field, such as a receiving coil.

The at least one receiving coil may be configured to receive a magnetic field provided by the at least one transmitting coil. Thus, the at least one receiving coil may be configured to inductively couple with the at least one transmitting coil. Such inductive coupling may be magnetic flux coupling. Thus, magnetic flux is a measure of the total magnetic field passing through a given surface. Thus, the magnetic flux is related to the number of magnetic field lines (i.e., the density of the magnetic field lines) of the magnetic field passing through a given surface. The magnetic flux coupling may be influenced by a specific target on which the magnetic field generated by the transmitter coil impinges and which influences the direction of the magnetic production line of the magnetic field. The magnetic field thus influenced can also be measured by the receiving coil. Thus, the morphology of a particular target may be constituted by a structure defining a preferred direction of how the target affects the trend of the magnetic field lines. Thus, the shape or morphology of the target may influence the alignment of the magnetic field lines in a preferred direction. Thus, the magnetic flux coupling between the at least one transmitting coil and the at least one receiving coil is highest if the at least one receiving coil is located within the preferred direction and thus the magnetic field lines generated by the at least one transmitting coil are aligned in the direction of the receiving coil. When the target is moved and thus the magnetic field is influenced again in a different way, this situation changes again, since the preferred direction has changed. Thus, the magnetic flux coupling between the at least one transmitting coil and the at least one receiving coil is different for different target locations. This knowledge allows sensing the position of the target based on measurements taken by the at least one receiving coil.

The at least one transmitting coil and the at least one receiving coil may each be configured to change its mode of operation from a transmitting magnetic field to a receiving magnetic field, and vice versa. Thereby, the at least one transmitting coil may change its operation mode from generating a magnetic field to receiving a magnetic field and may thereby become one of the at least one receiving coil. Similarly, the at least one receiving coil may be configured to change its mode of operation from receiving a magnetic field to generating a magnetic field, and may thereby become one of the at least one transmitting coil. Furthermore, it is contemplated that different coils may vary their sensitivity and/or the strength of the magnetic field they generate.

The non-sensing elements, e.g. evaluation circuits, may be located at a second side of the non-conductive substrate, opposite to the first side. The evaluation circuit may be arranged, for example, on a surface of the second side of the substrate, or may be at least partially integrated into the second side of the substrate, similar to the conductive coil at the first side. Also here, the elements on the second side of the substrate may be covered with a protective layer, which may cover the second side completely or partially and may allow conductors to cross.

The evaluation circuit at the second side of the non-conductive substrate may be a semiconductor device. The evaluation circuit may also be referred to as an integrated circuit or die. The evaluation circuit can be connected to at least one of the at least two electrically conductive coils by means of an electrically conductive connection. Further, the evaluation circuit may be configured to receive a signal indicative of the sensed magnetic field from the at least one receiving coil. Alternatively or additionally, the evaluation circuit can also be connected to other of the at least two electrically conductive coils by means of electrically conductive connections. The evaluation circuit may thereby be configured for controlling the current or voltage supplied to the at least one transmitting coil. The connection may be direct or indirect.

The signal received by the evaluation circuit from at least one of the at least two conductive coils may be indicative of the induced current or voltage and/or the strength of the magnetic field sensed by the sensor. For example, the signal may be a current or a voltage, wherein the current may be an induced current and the voltage may be an induced voltage. The evaluation circuit may evaluate the sensed magnetic field using the received signal, wherein evaluating the sensed magnetic field may include processing the received signal. The evaluation circuit may report to another entity the direct signal received from the receive coil or the result of the processing (i.e., the indirect measurement signal). Thus, reporting may include providing the results of the processing to another entity or directing or forwarding the received signal to another entity.

Likewise, the evaluation circuit may provide a current to at least one of the at least two conductive coils, which may be referred to as a transmit coil, such that the transmit coil provides a magnetic field. Alternatively or additionally, the evaluation circuit may control a current or a voltage supplied to the at least one transmitting coil. These processes of providing a current or voltage to the transmit coil and/or controlling the current or voltage to the transmit coil may also be referred to as driving the transmit coil. The evaluation circuit may autonomously drive the transmit coil, wherein the evaluation circuit may drive the transmit coil continuously or in a pulsed manner. Also, the evaluation circuit may drive the transmitting coil with an alternating current in order to induce an alternating magnetic field.

Since the evaluation circuit may autonomously drive the at least one transmitting coil and may receive signals from the at least one receiving coil, it may also be said that the evaluation circuit may operate the at least two conductive coils. Thereby, the operating coil may comprise at least one of: controlling a magnetic field, sensing a magnetic field, evaluating a magnetic field, and/or reporting the results of sensing or evaluating a magnetic field.

The at least two electrically conductive coils and the evaluation circuit may be connected by means of electrically conductive connections. The conductive connection may comprise any type of connection suitable for providing or receiving a current or voltage or signal. Preferably, the conductive connection may comprise a wire in or on a non-conductive substrate, a channel in a substrate comprising a wire, or a circuit path such as a printed circuit board trace. As such, the conductive connections may include a conductive material such that the conductive connections are configured to conduct electrical current. The connection may thus be direct or indirect. The connections may also be formed by conductive layers within the substrate or by other conductive structures within the substrate.

The conductive connections between the at least two conductive coils and the evaluation circuit are configured to enable transmission of current or voltage between the at least two conductive coils and the evaluation circuit. The transmitted current or voltage may also be referred to as a signal. For example, the evaluation circuit may be configured to receive a signal, e.g. in the form of a voltage and/or a current, from at least one of the at least two conductive coils. However, the evaluation circuit may also be configured for driving at least one of the at least two conductive coils, wherein driving the coil means that a voltage and/or a current is applied to the coil via the conductive connection. Such applied voltage and/or current may be, for example, a constant voltage and/or current or an alternating voltage and/or current.

The conductive connections between the at least two conductive coils and the evaluation circuit may be incorporated in the substrate. For example, the conductive connection may penetrate the entire thickness of the substrate from the first side to the second side. Also, it may be possible that the substrate comprises at least one hole or passage penetrating the entire thickness of the substrate such that the electrically conductive connection may at least partially pass through said at least one hole or passage. In addition, the substrate may also include a conductive layer that provides a conductive connection. The electrically conductive connection may be formed by a direct or indirect electrically conductive path, i.e. connecting the at least two coils with the evaluation circuit, directly or via further active and/or passive elements.

In one embodiment of a sensor package according to the present invention, the non-conductive substrate may comprise an electrically insulating, non-metallic, and/or low dielectric loss material. For example, the non-conductive substrate may comprise plastic, glass, or ceramic material. The use of at least one of these electrically insulating, non-metallic, and/or low dielectric loss materials further reduces eddy current generation in the sensor package according to the invention, since these materials are insensitive or at least sensitive to magnetic fields only to a small extent. Therefore, no or only very small eddy currents are generated in the substrate material itself. Furthermore, these materials act as shields to protect the evaluation circuit from the measured and/or generated magnetic field.

In one embodiment of a sensor package according to the invention, the non-conductive substrate may be configured to impart substantial structural rigidity. In the solutions known from the prior art, the structural rigidity can be established only by means of the lead frame used as the central base. Since the substrate is used as a central base in a sensor package according to the invention, the substrate may be configured to provide at least some or all of the structural rigidity of the sensor package. Structural rigidity in the sense of the present invention means that the substrate comprises a structure or morphology that is stable with respect to the lifetime of the sensor package during any situation related to the intended use of the sensor. Structural rigidity may also be referred to as stability, durability, and/or durability. However, structural rigidity may also be provided by the lead frame. Furthermore, structural rigidity may be achieved by molding or overmolding the sensor element with a mold material.

In an embodiment of the sensor package according to the invention, the non-conductive substrate may comprise connection pads at the second side of the substrate for connecting the at least two conductive coils with the evaluation circuit. The connection pads may be connected with at least two conductive coils located at a first side of the substrate and may be configured to be connected with an evaluation circuit located at a second side of the non-conductive substrate. For example, the connection pads may be bonding pads or wire pads. In case the evaluation circuit is located on the second side of the substrate as a flip chip, the connection pads may be configured to be connected with the evaluation circuit by wire bonding or by bump bonding. The connection pads may be connected to, or may be part of, electrically conductive connections between the at least two electrically conductive coils and the evaluation circuit. Further, the connection pads may be connected to the at least two conductive coils by at least one wiring penetrating the non-conductive substrate. Alternatively, at least part of the connection pad may penetrate the non-conductive substrate, such that said part of the connection pad may extend to the first side of the non-conductive substrate and may be connected to the at least two non-conductive coils.

In an embodiment of the sensor package according to the invention, the evaluation circuit is mounted as a flip chip on the second side of the substrate. Thereby, the substrate may comprise respective connections allowing the evaluation circuit to be connected to the electrically conductive connections and thereby to the at least two electrically conductive coils.

In an embodiment of the sensor package according to the invention, the at least two conductive coils may be at least partially integrated into the non-conductive substrate at the first side of the non-conductive substrate. For example, the at least two conductive coils may each comprise a volume, thereby not only extending in length and width to span an area but also having a height or thickness. At least one of the at least two electrically conductive coils may then be at least partially integrated into the non-conductive substrate such that, for example, a first portion of the volume of the coil is surrounded by the non-conductive substrate. According to one embodiment, at least a second portion of the volume of the coil is not surrounded by the non-conductive substrate. For example, the first portion may be located inside the non-conductive substrate and the second portion may be located on a surface of the non-conductive substrate. However, it is also possible that the volume of at least one of the at least two electrically conductive coils may be integrated completely into the substrate. In this case, the entire volume of the coil may be located inside the non-conductive substrate, such that the entire volume of the coil may be located below the surface of the non-conductive substrate. At least two conductive coils can also be integrated in the substrate at different heights.

In an embodiment of the sensor package according to the invention, the at least two electrically conductive coils may not structurally overlap each other. Thus, the at least two coils may be adjacent to each other but may not structurally overlap each other. Structurally overlapping may also be referred to as at least partially interlacing, staggering, or interlacing. Thus, the at least two coils are each positioned in a specific volume of the substrate in such a way that the volume of a specific one of the at least two coils is not located in a part of the volume belonging to another one of the at least two coils. In detail, a first coil of the at least two coils may define a first continuous volume having no portion in common with a second continuous volume that may be defined by a second coil of the at least two coils.

In an embodiment of the sensor package according to the invention, the at least two electrically conductive coils at least partially and structurally overlap. Thereby, the spatial extensions of the at least two coils at least partially overlap. For such an overlap, the at least two coils may be implemented on different layers on or in the substrate. Thus, a plane in which at least one of the two coils is arranged may be spatially offset with respect to a plane in which at least another of the at least two coils is arranged. It can also be said that at least one of the two electrically conductive coils is located below the other of the at least two electrically conductive coils.

In an embodiment of the sensor package according to the invention, one of the at least two electrically conductive coils may provide a magnetic field and the other of the at least two electrically conductive coils receives the magnetic field. Thereby, the at least one receiving coil may be coupled to the at least one transmitting coil.

In an embodiment of the sensor package according to the invention, the sensor package may comprise at least three conductive coils located at a first side of the non-conductive substrate. Thus, the at least three conductive coils may be configured to switch their mode of operation from generating a magnetic field to receiving a magnetic field. Thus, in one configuration, at least one of the three conductive coils may generate a magnetic field while the other two conductive coils receive the magnetic field. In another configuration, two of the three conductive coils may generate magnetic fields while the other conductive coil receives a superposition of the respective magnetic fields.

In an embodiment of the sensor package according to the invention, the sensor package may further comprise a lead frame, which may be arranged only at the second side of the substrate. The lead frame may be used for the assembly of elements located at the second side of the non-conductive substrate. For example, the evaluation circuit may be at least partially placed on the lead frame. However, it may also be possible that the evaluation circuit is placed directly on the non-conductive substrate and the leadframe only at least partially surrounds the evaluation circuit or that the leadframe is positioned in close proximity to the evaluation circuit. The evaluation circuit may be connected to the lead frame by wires. In a one-dimensional or two-dimensional extension of the spatial extension of the substrate, the lead frame may extend 20%, 30%, 50% or 80% over the spatial extension of the substrate. The lead frame may provide additional structural rigidity to the substrate. Since the lead frame of this embodiment of the invention may be located only at the second side of the non-conductive substrate, the generation of eddy currents in the lead frame may be reduced. Further, the leadframe may be located at a position at the second side that is sufficiently far away from the at least two electrically conductive coils such that small eddy currents that may be generated in the leadframe do not affect the induced current or induced voltage indicative of the sensed magnetic field. Thereby, it can be said that the at least two electrically conductive coils can be shielded from undesired eddy currents, since the elements in which eddy currents may be generated are sufficiently far away from the position of the at least two electrically conductive coils.

In an embodiment of the sensor package according to the invention, the lead frame may be at least partially integrated into the substrate at the second side of the non-conductive substrate.

In one embodiment according to the invention, the evaluation circuit may be connected to the lead frame by wire bonding, or mounted onto the lead frame as a flip chip, or may be connected to the lead frame via a substrate.

In an embodiment of the sensor package according to the invention, the at least two conductive coils at a first side of the non-conductive substrate may define a first area, and the evaluation circuit may be located within a second area at a second side of the non-conductive substrate, the second area being directly opposite the first area. Thus, both regions may have the same size. Those skilled in the art will recognize that the die need not fill the entire second area, but may be located within the second area at the second side of the substrate. Since the assembly of the components on the non-conductive substrate reliably reduces eddy currents, it is possible to assemble at least two inductor coils and the evaluation current in the region of the first side and the second side directly opposite one another, respectively.

In an embodiment of the sensor package according to the invention, the sensor package comprises at least one terminal, wherein the at least one terminal is one of a supply terminal, an input terminal and an output terminal, wherein the at least one terminal is connectable to the evaluation circuit and/or to at least one of the at least two electrically conductive coils. The at least one terminal and the substrate may be soldered or glued. Further, it is also possible to solder or glue the at least one terminal to a lead frame, which may be located at the second side of the non-conductive substrate. At least one terminal may be configured for connecting the sensor to an entity using the sensor. Thus, at least one terminal may be connected to a physical printed circuit board. At least one terminal may be configured to enable communication between the sensor and the entity. For example, the sensor package may receive a supply voltage via one terminal, which provides power for the operation of the sensor. Additionally, the sensor may receive input information via the input terminal, which may be configured to control the sensor. The input information may, for example, include information indicating that the sensor may start or stop its operation sensing the magnetic field. Further, the input information may also be a command input, an internal or external test input, or an error signal. The evaluation circuit may provide an output signal indicative of the sensed magnetic field to the device via the output terminal. Thus, the output signal may comprise raw data (i.e. a direct signal from the coil) or processed data (i.e. an indirect signal, i.e. the result of a processed direct signal), wherein the raw data or processed data may be indicative of the sensed magnetic field or the sensed induced current or induced voltage. It is also contemplated that the processed data includes positional information about objects that move in the vicinity of the sensor and may affect magnetic flux coupling. The raw data may, for example, comprise an induced current or an induced voltage that may be sensed by at least one of the at least two conductive coils. The processed data may include information about the sensed magnetic field, which may be related to the induced current or induced voltage. The processed data may be a current or a voltage provided by or controlled by the evaluation circuit. Even though only one configuration of terminals is described herein, it will be clear to those skilled in the art that other configurations are also contemplated. For example, two terminals may be configured as supply terminals, e.g., for VDD and GND, and the other terminal may be a combined input/output terminal. However, other configurations and numbers of terminals are possible.

In an embodiment of the sensor package according to the invention, the sensor package may comprise at least one passive component. The passive components may also be referred to as passive components, additional components, and may be blocking capacitances and/or resistors for evaluating the circuit power supply system, capacitors for electromagnetic compatibility (EMC) emissions, and/or passive inductors. The passive components may be mounted on a lead frame or may be mounted on a non-conductive substrate. The passive components may for example be glued or soldered to the lead frame or glued or soldered to the substrate, respectively. Alternatively, the passive components may be distributed elements implemented within a non-conductive substrate. For example, the non-conductive substrate may include circuitry that may be printed onto the non-conductive substrate, and portions of the circuitry may be configured to form passive components.

In an embodiment of the sensor package according to the invention, the sensor package may be at least partially encapsulated by the mold material. Encapsulating the sensor package by the mold material may protect the components of the sensor package from its environment. For example, the mold material may provide protection from corrosion and/or from physical damage such as impact. The mold material may be a non-conductive mold material, such as an epoxy-based molding compound or polyphenylene sulfide (PPS).

In one embodiment of a sensor package according to the present invention, the non-conductive substrate may comprise a redistribution layer. Thus, the redistribution layer is part of the non-conductive substrate, which may be configured for routing the conductive connections between the evaluation circuit and the lead frame. Thereby, the conductive connection may be at least partially located at the redistribution layer. Thus, the conductive connectors may be on the redistribution surface, may be at least partially inside the redistribution layer, and/or may penetrate the redistribution layer.

In an embodiment of the sensor package according to the invention, the dimensions of the package depend on the internal components and on the capabilities of the substrate material. For example, involving non-electrical conductionThe printing of the substrate for the volume of the substrate may be larger than the evaluation circuit. The size of the package may be, for example, 5^-10x 5^-10mm². In one embodiment, the package may have 6x 9mm²Or 6x 6.5mm²The size of (c). The evaluation circuit may have a 1mm²、10mm²Or 20mm²The size of (c). In a preferred embodiment, the at least two coils may have dimensions similar to those of the package, wherein the dimensions of the coils are 1mm smaller in each direction in order to ensure that the coils can be completely moulded by the mould material.

Drawings

The following description and the annexed drawings set forth in detail certain illustrative aspects of the sensor package described above. These aspects are indicative, however, of but a few of the various ways in which the principles of various embodiments may be employed and the described embodiments are intended to include all such aspects and their equivalents.

In the drawings, like reference numerals generally refer to like parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention.

In the following description, embodiments of the invention are described with reference to the following drawings, in which:

fig. 1a, 1b show plan views of a sensor package according to an example of embodiment of the invention, wherein the plan views are plan views of a surface of a second side of a substrate;

FIG. 2 shows a plan view of an exemplary sensor package according to one embodiment of the invention, wherein the plan view is a plan view of a surface of a first side of a substrate;

fig. 3a, 3b show side views of sensor packages according to examples of embodiments of the invention.

Fig. 4a shows a plan view of a sensor package according to an example of embodiment of the invention, wherein the plan view is a plan view of a surface of the first side of the substrate.

Fig. 4b shows a graphical representation of the magnetic flux of the sensor arrangement of fig. 4 a.

Fig. 5 to 8 show plan views of sensor packages according to examples of embodiments of the present invention, wherein the plan views are plan views of a surface of a first side of a substrate.

Detailed Description

The following detailed description refers to the accompanying drawings that show, by way of illustration, specific details and embodiments in which the invention may be practiced.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments or designs.

Fig. 1a shows a plan view of an exemplary sensor package 100 according to an embodiment of the invention. In detail, fig. 1a shows a plan view of the surface of the second side 125 of the non-conductive substrate 105. The non-conductive substrate 105 is configured for supporting at its second side 125 several elements, for example, an evaluation circuit 120. Thus, the evaluation circuit 120 and/or further elements may be mounted directly on the substrate 105 or may be physically located only on the second side 125 of the substrate 105, but not in direct contact with the substrate 105. For example, a protective layer may be arranged between the evaluation circuit 120, the further elements and the substrate 105. Further, the evaluation circuit and/or further elements may also be integrated wholly or at least partially into the second side 125 of the substrate 105.

The evaluation circuit 120 may also be referred to as an integrated circuit or die. The evaluation circuit 120 may be a semiconductor device. In the example of embodiment shown here, the evaluation circuit 120 is located at the second side 125 of the non-conductive substrate 105 and is mounted on the non-conductive substrate 105. As such, elements located at the second side 125 of the non-conductive substrate 105, such as the evaluation circuit 120, may be located on a surface at the second side 125 of the non-conductive substrate 105 or may be at least partially integrated into the volume of the non-conductive substrate 105.

The second side 125 of the non-conductive substrate 105 may further comprise a connection pad 130, the connection pad 130 being connected to the evaluation circuit 120. In the exemplary embodiment shown in fig. 1a, the evaluation circuit 120 is connected to the connection pads 130 by means of wires. Further, the connection pads 130 are configured to be connected to at least two conductive coils located at the first side 115 of the non-conductive substrate 105 and described in more detail below with reference to fig. 2. The connection pads 130 may be connected to at least two conductive coils 110a-c as shown in fig. 2 by means of connections penetrating the non-conductive substrate 105. For example, at least a connection portion of the connection pad 130 may extend through the non-conductive substrate 105 to the first side 115 of the non-conductive substrate 105. At the first side 115 of the non-conductive substrate 105, connection portions of the connection pads 130 may be connected to at least two conductive coils 110 a-c. In another example, the non-conductive substrate 105 may include at least one channel configured to connect the first side 115 and the second side 125 of the non-conductive substrate 105. Thus, the at least one channel may include at least one conductive connection, such as a wire, configured to connect the at least two conductive coils 110a-c and the bond pad 130. However, it is also possible that the at least one conductive wire configured to connect the bond pad 130 and the at least two conductive coils 110a-c passes through the non-conductive substrate 105 without the presence of a particular via in the non-conductive substrate 105. Furthermore, it is also possible that the substrate 105 itself comprises a conductive layer or other conductive structure allowing a conductive connection between the evaluation circuit 120 and the at least two conductive coils 110 a-c.

Further, the sensor package 100 shown in FIG. 1a comprises passive components 150a-d as further elements. These passive components 150a-d may be referred to as passive components, add-ons, or add-ons, and may include blocking capacitances and resistors for evaluating the power system of the circuit 120, capacitors for electromagnetic compatibility (EMC) emissions, and/or passive inductors. In the example embodiment shown here, the passive components 150a-d are mounted to a non-conductive substrate 105. The passive components 150a-d may be soldered or glued to the non-conductive substrate 105. Although not shown here, where the second side 125 may comprise a lead frame, the passive components 150a-d may be at least partially mounted to the lead frame. In fig. 1a, each passive component 150a-d is depicted as a discrete element, i.e., a localized element, mounted on the non-conductive substrate 105 as a coherent element, as indicated by blocks 150 a-d. However, it is also possible that the passive components 150a-d are distributed elements implemented within the non-conductive substrate 105. For example, the non-conductive substrate 105 may include circuitry, and portions of the circuitry may be configured to form the passive components 150 a-d. Such circuitry may be printed or etched onto the non-conductive substrate 105.

Also, the sensor package 100 shown in FIG. 1a comprises several terminals 135,140,145a-n, in particular at least one supply terminal 135, at least one input terminal 140, and several output terminals 145 a-n. Those skilled in the art will appreciate that even though a specific number of terminals are shown here as such, any suitable number of terminals may be implemented. Terminals 135,140,145a-n may be configured to connect the sensor to an entity, i.e., a device (not shown here), using the sensor. For example, terminals 135,140,145a-n may be configured to connect the sensor with a printed circuit board. Further, the terminals 135,140,145a-n may be configured to provide information obtained by the sensor package 100 to the environment of the sensor package 100, e.g., to a device using the sensor.

Supply terminal 135 may be configured to provide a supply voltage to sensor package 100. As such, the supply voltage may enable operation of the sensor package 100. The input terminals 140 may be configured to provide input signals to the sensor package 100. The input signal may be, for example, a current or a voltage that may be used to control the sensor. For example, the input signal may instruct the sensor to begin or complete its operation, e.g., by beginning or completing a process of sensing the magnetic field. Output terminals 145a-n may be configured to transmit data from sensor package 100 to at least one other device. Sensor package 100 may include any number of output terminals 145a-n, such output terminals 145a-n being adapted to communicate with at least one other device. For example, at least one output terminal is connected to the evaluation circuit 120 for providing output data of the sensor package 100. The output data may, for example, comprise the result of sensing the magnetic field. However, the output data may alternatively or additionally comprise the sensed raw data. This raw data may also be referred to as raw data and may be, for example, an induced current or voltage sensed by at least one of the at least two coils.

Sensor package 100 as depicted in fig. 1a may be encapsulated with mold material 155. The mold material protects the sensor package 100 from its environment. For example, the mold material may be configured to protect the sensor 100 from corrosion and/or physical damage, such as, for example, impact. Further, the mold material 155 may shield the sensor package from its environment. The mold material may be a non-conductive mold material, such as an epoxy-based molding compound or polyphenylene sulfide (PPS).

Although the elements of the sensor package 100 located at the second side 125 of the non-conductive substrate 105 are mounted onto the non-conductive substrate 105 in fig. 1a, it is also possible that the second side of the non-conductive substrate 105 may comprise a lead frame. Fig. 1b depicts a sensor package 100a with such a lead frame 190, to which lead frame 190 further elements 150a-d may be at least partially mounted. However, the lead frame 190 may include a minimum size and cover only a small portion of the non-conductive substrate 105 in order to prevent the generation of eddy currents. In the example embodiment shown in fig. 1b, the lead frame 190 may comprise a plurality of portions 190, 190 a-c. The lead frame 190 may also be at least partially integrated into the substrate 105. Furthermore, even though not shown here, the lead frame 190 may also be connected to the evaluation circuit 120, or the evaluation circuit 120 may be at least partially mounted on the lead frame 190.

As already depicted in fig. 1a, fig. 2 shows a plan view of a sensor package 100 according to an example of an embodiment of the invention. In detail, fig. 2 shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. The sensor package 100 according to the example embodiment includes three conductive coils 110a-c, the three conductive coils 110a-c being located at a first side 115 of the non-conductive substrate 105. The three conductive coils 110a-c may be printed, etched, soldered, or glued onto the substrate 105, for example. Thus, the three conductive coils 110a-c may be located on a surface of the non-conductive substrate 105 or may be at least partially integrated in the non-conductive substrate 105. It is also possible that at least one of the three conductive coils 110a-c is integrated entirely in the non-conductive substrate 105 and the other conductive coils may be disposed on the surface of the substrate 105 if the three conductive coils 110a-c are at least partially integrated into the non-conductive substrate 105. However, it is also possible that all three conductive coils 110a-c are integrated or buried into the substrate. The conductive coils 100a-c may also be located at the first side 115 of the substrate 105 at different heights, all or at least in part. For example, at least two of the three coils 110a-c are integrated into the substrate 105, while one of the at least three coils 110a-c is located at the first side 115 of the substrate 105. However, those skilled in the art will also recognize that different positioning of the coils 110a-c is possible. Furthermore, the three coils 110a-c may be coated with a coating material. The three conductive coils 110a-c shown here are illustratively represented by a single loop, but those skilled in the art will recognize that other configurations are possible. Furthermore, it is also clear to the person skilled in the art that other numbers or arrangements of the electrically conductive coils are possible without departing from the scope of the invention.

The at least three conductive coils 110a-c of the sensor package 100 as shown in fig. 2 may include at least one coil, such as coil 110a, that generates a magnetic field. The at least one coil 110a may also be referred to as a providing coil, a generating coil, or a transmitting coil. Further, the remaining conductive coils 110b and 110c may receive a magnetic field. The coils 110b and 110c may also be referred to as receiving coils.

The receive coils 110b and 110c may be configured to receive the magnetic field provided by the transmit coil 110 a. Upon reception, the magnetic field may induce an inductive current or voltage in the receiving coils 110b and 110 c. It can be said that the receive coils 110b and 110c can be coupled to at least one transmit coil 110 a. Such coupling may be referred to as inductive coupling and may be affected by an object (now shown here) configured to move in proximity to the coils 110 a-c. Thus, it will be clear to those skilled in the art that the magnetic field generated by the at least one transmit coil 110a comprises a gradient of magnetic flux that results in eddy currents flowing within the target. These eddy currents in the target affect the magnetic field generated by the transmit coil 110a and thereby affect the magnetic flux coupling between the at least one transmit coil 110a and the receive coil 110 b. If more than one transmitting coil is used, the magnetic field consists of a superposition of the at least two generated magnetic fields. In order to also encounter magnetic field gradients in this case, the magnetic flux of the generated magnetic field may be different and/or the direction of the generated magnetic field may be different. In general, it can be said that the magnetic flux of the impinging magnetic field at the target generates eddy currents that will flow along discrete paths defined by the structure of the target. Thereby, some of these eddy currents may cancel each other out, while others of these eddy currents will be enhanced depending on the geometry of the structure and/or the magnetic flux impinging on the target. For example, if the target has a structure with the same inductance, the impinging magnetic field needs to exhibit a gradient so that the partially and/or purely induced eddy currents are not cancelled out, whereas if the target has a structure with a different inductance between adjacent structures, the magnetic field need not exhibit a magnetic gradient. This can thus be taken into account for different collision magnetic field situations for the geometry of the structure and thus for the shape or form of the object. This can be exploited, for example, to increase the eddy currents in a preferred direction of the target. Thereby, the magnetic field generated by the eddy currents and thus the influence of the target is increased in turn. It can be said that the target can affect the magnetic flux coupling between the transmit coil 110a and each of the receive coils 110b and 110 c. Thus, the target may be configured to influence the direction of the magnetic field lines of the magnetic field, e.g. by aligning the magnetic field lines with a specific direction, wherein the specific direction may be derived from the morphology of the target. Depending on the position of the target relative to the at least two receive coils 110b and 110c, the particular direction in which the magnetic field lines are aligned may be different. Thus, the magnetic flux and the magnetic field that can be sensed by the at least two receiving coils 110b and 110c may depend on the position of the target. The sensed magnetic field may thus be indicative of the position of the target or a change in the position of the target caused, for example, by movement, which may be rotational movement or linear movement. To facilitate alignment of the magnetic field lines, the target may comprise an electrically conductive material. Since the sensor package 100 may only include sensing elements at the first side 115 of the non-conductive substrate 105, these sensing elements (i.e., the three coils 110a-c) may be placed at a short distance from the target, which improves alignment of the magnetic field lines. The sensor package 100 may also include means for storing an expected current or voltage value for a particular target. These values may be stored during a calibration run for a particular target or may be modeled results. By means of a comparison between these expected values and the values actually measured by the at least two receiving coils 110b and 110c, the position of the target can be determined. The comparison may be performed, for example, by the evaluation circuit 120, which may then provide the position of the target as an output.

However, the at least one transmitting coil 110a and the receiving coils 110a-c of the sensor package according to the invention may also be configured for magnetic flux coupling. In the case of magnetic flux coupling, the coupling does not depend primarily on the magnitude of the magnetic field but on the direction and/or density of the magnetic field lines of the magnetic field. Such coupling may be subsequently referred to as magnetic flux coupling, as a change in the direction and/or density of the magnetic field lines changes the magnetic flux of the respective region experiencing the change in the direction and/or density of the magnetic field lines.

The conductive coils 110a-c may also be configured to change their mode of operation during operation. For example, one conductive coil may be a transmit coil in one instance of time and a receive coil in another instance of time. Thus, different configurations are possible for the three conductive coils 110a-c as depicted in fig. 2. For example, the two conductive coils 110a and 110b may each generate a magnetic field, while the conductive coil 110c may receive, for example, a superposition of the respective generated magnetic fields, both of which are affected by the target (not shown). In another instance of time, the configuration may change, and the correspondingly named coils may assume different modes of operation. Thus, the conductive coils 110a-c may individually and dynamically change their mode of operation from receiving a magnetic field to generating a magnetic field such that magnetic flux coupling may be sensed from different locations to enhance the position determination capabilities of the sensor package 100. This change in operating mode will be described in more detail below.

Further, as already depicted in fig. 1a, fig. 2 shows a back view of terminals 135,140,145a-n and mold material 155, which mold material 155 encapsulates sensor package 100.

Fig. 3a shows a side view of a sensor package 100 according to an example of embodiment of the invention as already depicted in fig. 1 and 2. The non-conductive substrate 105 includes a first side 115 and a second side 125. In this example, each of the first side 115 and the second side 125 of the non-conductive substrate 105 includes a thickness, which is depicted by means of a bracket near the reference numerals 115, 125 in fig. 3 a. As depicted in fig. 3a, the thickness of the first side 115 and the thickness of the second side 125 may be equal. However, it is also possible that the first side 115 and the second side 125 have different thicknesses. For example, the first side 115 may be limited to only the surface of the substrate 105 or may be limited to a thin layer of the substrate 105, while the second side 125 may be substantially thicker than the first side 115. However, in another example, the first side 115 may be substantially thicker than the second side 125. Both sides 115, 125 are opposite each other. Thus, first side 115 and second side 125 may be in contact with each other, or may be separated by at least one layer that is neither part of first side 115 nor part of second side 125. Even though the different sides 115 and 125 are depicted as solid blocks in the embodiment example shown here, the sides 115 and 125 may also comprise a layer structure. The layer structure may comprise a non-conductive layer and a conductive layer. Wherein the conductive layer may act as a conductive connection for the sensor element.

The first side 115 and the second side 125 of the non-conductive substrate 105 may be formed from a layer of substrate material. For example, the non-conductive substrate 105 may include at least two layers, wherein the first side 115 includes at least a first layer of the non-conductive substrate 105 and the second side 125 includes at least a second layer of the non-conductive substrate 105.

Where the non-conductive substrate 105 includes a layer, the non-conductive substrate 105 may include a redistribution layer. The distribution layer may be configured to route conductive connections between the three conductive coils 110a-c and the evaluation circuitry 120. Thus, the redistribution layer may divide the non-conductive substrate 105 into at least two portions, which may be equal to the first side 115 and the second side 125 of the non-conductive substrate 105. The redistribution layer may be part of the first side 115 of the non-conductive substrate 105, may be part of the second side 125 of the non-conductive substrate 105, or may not be part of the first side 115 and the second side 125 of the non-conductive substrate 105.

As depicted in fig. 3a, the first side 115 of the non-conductive substrate 105 may include three conductive coils 110 a-c. The three conductive coils 110a-c can be positioned at the first side 115 of the non-conductive substrate 105 in such a way that they are disposed on the surface of the first side 115 of the non-conductive substrate 105. Thus, the three conductive coils 110a-c may be mounted onto the non-conductive substrate 105, may be attached to the non-conductive substrate 105, or may be printed, etched, or soldered to the non-conductive substrate 105. Further, at least one of the at least three electrically conductive coils 110a-c may be coated with a protective layer.

The evaluation circuit 120 is located at a second side of the non-conductive substrate 105. The evaluation circuit 120 may be disposed on a surface of the non-conductive substrate 105. To achieve this, the evaluation circuit 120 may, for example, be mounted on the non-conductive substrate 105 or attached to the non-conductive substrate 105.

The second side 125 of the non-conductive substrate 105 may also include further elements such as passive components 150a-d, connection pads 130, and terminals 135,140,145 a-c. Similar to the three conductive coils 110a-c and the evaluation circuit 120, these elements may be located at the second side 125 of the non-conductive substrate 105. Additionally, terminals 135,140,145a-n can be exposed from the second side 125 of the non-conductive substrate 105 for connection to another device.

Fig. 3b shows a side view of a sensor package 100 according to an example of embodiment of the invention as already depicted in fig. 1 and 2. In the example of embodiment shown here, the electrically conductive coils 110a-c are integrated into the substrate 105 on the first side 115 and the further elements 150a-d are at least partially integrated into the substrate 105 on the second side 125. Additionally, terminals 135,140,145a-n can be exposed from the second side 125 of the non-conductive substrate 105 for connection to another device.

In both example embodiments depicted in fig. 3a and 3b, the three conductive coils 110a-c are the only conductive elements located at the first side 115 of the non-conductive substrate 105. All further conductive elements (i.e. non-sensing elements) of the sensor package are located at the second side 125 of the non-conductive substrate 105. Furthermore, even if the embodiment example as shown in fig. 3a relates to elements arranged on a surface of a substrate, whereas the embodiment example shown in fig. 3b relates to elements at least partially integrated into the substrate 105, it is clear to a person skilled in the art that a mixture of these two embodiment examples is covered by the scope of the invention. Thus, some elements may be partially or fully integrated into the substrate 105, while other elements may be arranged on the surface of the substrate 105 on the respective sides 115, 125 of the substrate 105.

Fig. 4 to 8 show further embodiment examples of sensor packages according to the invention with different sensing element arrangements.

Fig. 4a shows a plan view of an exemplary sensor package 200 according to an embodiment of the invention. In detail, fig. 4a shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. The sensor package 200 according to the example embodiment includes seven conductive coils 210a-f, 220, the seven conductive coils 210a-f, 220 being located at the first side 115 of the non-conductive substrate 105. Where coils 210a-f are receive coils and coil 220 is a transmit coil (depicted as a circular loop in dashed lines). The transmit coil 220 has a significantly larger diameter than the receive coils 210 a-f. The receive coils 210a-f are arranged on a circular line. In detail, they are arranged on the outer circumference formed by the transmitting coils, wherein the spatially extending center points of the receiving coils 210a-f are evenly distributed along the circumference. Thus, it can be said that the receiving coils 210a-f at least partially and spatially overlap the spatial extension of the transmitting coil 220. The receive coils 210a-f may thus be implemented in one plane (e.g., one layer of the substrate 105 of the package 200), while the transmit coil 220 may be implemented in another plane (e.g., another layer of the substrate 105 of the package 200).

If the area covered by the transmit coil 220 is larger than the area covered by at least one of the receive coils 210a-f, the magnetic field generated by the transmit coil 220 induces a significant current/voltage in the receive coils 210 a-f. The portion of the induced current or voltage that is not affected by the position of the target (whose position should be sensed) is referred to as the common mode current or voltage, respectively, or collectively as the common mode signal. The common mode signal does not carry any positional information about the target. However, with the arrangement of the coils 210a-f and 220 as shown in fig. 4a, such common mode signals are suppressed. This suppression is explained in the context of fig. 4 b.

Fig. 4b shows a coil arrangement as depicted in fig. 4 a. The receive coils 210a-f at least partially and spatially overlap the transmit coil 220. In the embodiment example shown here, the receiving coils 210a-f are arranged such that substantially half of their spatial extension overlaps with the spatial extension of the transmitting coil 220. It can also be said that half of the receiving coils 210a-f are located within the spatial extension of the transmitting coil 220, while the other half are located outside the spatial extension of the transmitting coil 220. This means that each of these halves of the receiver coils 210a-f is subjected to a different magnetic flux phi₁And phi₂Through, these magnetic fluxes are indicated as shaded areas of the receive coil 220. Also, different magnetic flux phi₁And phi₂Both generated by the same transmit coil 220, phi₁And phi₂Have different directions because of a magnetic flux phi₁Is part of the magnetic flux outside the transmitter coil 220 and another magnetic flux phi₂Is part of the magnetic flux inside the transmitter coil 220. The induced property (voltage or current) in the receiver coils 210a-f is the two magnetic fluxes phi₁And phi₂A superposition of the created sensing attributes. Magnetic flux phi for suppressing common mode signals₁And phi₂The effects on the receive coils 210a-f must cancel each other out. This is when the magnetic flux phi₁Is substantially equal to the magnetic flux phi₂The case when, because then the sensing property has substantially the same value, but one is positive and the other is negative. In the embodiment example shown here, this is achieved by arranging the receive coils 210a-f in such a way that half of the spatial extension of the receive coils 210a-f overlaps with the spatial extension of the transmit coil 220 and the other half does not overlap. However, it is clear to the skilled person that in other configurations other overlaps have to be used as well. It is therefore important that the magnetic flux phi outside the overlap region₁Magnetic flux phi inside the overlap region₂Substantially the same so that the two magnetic fluxes cancel each other. Since the magnetic flux is not linear, the two regions (and thus the overlapping region and the non-overlapping region) may be different in size. For example, since the overlapping region will encounter a higher magnetic flux than the non-overlapping region, the overlapping region needs to be substantially smaller than the non-overlapping region so that a sufficiently high magnetic flux is still encountered in the non-overlapping region to cancel the magnetic flux within the overlapping region. By this, common mode signals can be suppressed without having an influence on the available second magnetic field carrying position information of the target.

Fig. 5 shows a plan view of an exemplary sensor package 300 according to an embodiment of the invention. In detail, fig. 5 shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. Similar to sensor package 200 of FIG. 4, sensor package 300 includes six receive coils 310a-f and one transmit coil 320. In the embodiment example shown here, the transmitting coil 320 is implemented in a distributed manner. In the example of embodiment shown here, the spatial extension of the receiving coils 310a-f completely overlaps with the spatial extension of the transmitting coil 320. Although the transmit coil 320 and the receive coils 310a-f are completely overlapping in the example of embodiment shown here, it will be clear to a person skilled in the art that the overlap may also be smaller than that shown. In the embodiment example shown here, the transmitting coil 320 is realized as a wire in a spiral shape. The spiral may be substantially flat such that the spiral-shaped wires are arranged in a plane, e.g., in a layer of the substrate 105. The receive coils 310a-f may be arranged in a plane away from the plane of the transmit coil 320, for example, in another layer of the substrate 105, or on the substrate 105. This arrangement of the receive coils 310a-f and the transmit coil 320 has the advantage of being less sensitive to manufacturing tolerances between the coils. While the coil loops in the example of embodiment shown here are adjacent to each other, it is contemplated that they may also be spaced farther apart from each other so that only a limited number of coil loops will overlap with the receive coils 310 a-f. In other words, it can also be said that at least part of at least one loop of the transmitting coil 320 intersects at least part of the spatial extension of the receiving coils 310 a-f.

Fig. 6 shows a plan view of an exemplary sensor package 400 according to an embodiment of the invention. In detail, fig. 6 shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. The sensor package 400 includes six receive coils 410a-f and two transmit coils 420a, 420b (bold lines). Thereby, at least one transmitting coil 420b is arranged around the receiving coils 410 a-f. Thus, the spatial extension of the receiving sensor elements 410a-f completely overlaps the spatial extension of the transmitting coil 420 b. It will be clear to the person skilled in the art that the overlap may also be smaller than the shown overlap. Thus, in the example embodiment shown here, the transmit coil 420b is depicted as a single wire loop around the six receive coils 410 a-f. The other transmit coil 420a is disposed at the center defined by the centerlines connecting the differential pairs 410a/d, 410b/e, and 410 c/f. The further transmit coil 420a is not spatially overlapping with the receive coils 410 a-f. The use of two transmit coils 420a and 420b allows for rejection of common mode signals without the need for overlap of the transmit coils 420a and 420b with the receive coils 410 a-f. For example, by having more turns and/or more current flowing in the transmit coil 420a than the transmit coil 420b, rejection of common mode signals may be achieved. Thus, with this kind of arrangement, all coils may be arranged in the same plane, e.g. in the same layer of the substrate 105 or on the substrate 105.

The shapes of the receive and transmit coils are not limited to circular shapes as depicted in fig. 2, 4a/4b, 5 and 6. The coils may also be hexagonal or shaped like sectors of a circle, corresponding example embodiments being shown in fig. 7 and 8.

Fig. 7 shows a plan view of a sensor package 500 according to an example of a further embodiment of the invention. In detail, fig. 7 shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. In the example of embodiment shown here, six hexagonal-shaped electrically conductive coils 510a-f are present, which are arranged in a circle. Thus, each coil 510a-f may include a wire that is substantially in the shape of a hexagonal spiral. In the example embodiment shown here, the coils 510a-f are adjacent to each other. The coils 510a-f may be configured to generate a magnetic field or to receive a magnetic field. Further, they may be configured to change their mode of operation from generating a magnetic field to receiving a magnetic field, and vice versa. For example, in a first instance in time, coils 510a and 510d may be receive coils, while the remaining coils 510b/c/e/f are transmit coils. The coils 510a and 510d may form a differential pair and output a differential signal. A differential signal may thus be formed by forming a difference in the current or voltage values output by each of the receive coils of the differential sensor pair. Thus, one value of one receive coil represents the decremented number and another value of the other receive coil represents the decremented number of the difference. By performing such a differential measurement, substantially similar effects acting on the two receive coils are eliminated. For example, stray fields carrying magnetic fluxes that similarly affect the two receive coils are eliminated due to the build-up of the difference. In another example of time, coils 510b and 510e may be receive coils, while the remaining coils 510a/c/d/f are transmit coils. In this time instance, coils 510b and 510e may form a differential pair and output a differential signal. In yet another example of time, coils 510c and 510f may be receive coils, while the remaining coils 510a/b/d/e are transmit coils. In this time instance, coils 510c and 510f may form a differential pair and output a differential signal. The different differential signals may then be combined to determine the location of the target. It is clear that any arbitrary cyclic shift can be performed even though a clockwise cyclic shift of the receiving coil is described herein. Further, even though it is described that a differential pair is formed and a differential signal is outputted, it is clear to those skilled in the art that each coil 510a-f may individually output a signal. Furthermore, it is clear that all coils 510a-f can independently change their operation mode from a receive mode to a transmit mode.

Fig. 8 shows a plan view of an exemplary sensor package 600 according to an embodiment of the invention. In detail, fig. 8 shows a plan view of the surface of the first side 115 of the non-conductive substrate 105. The sensor package 600 includes six coils 610a-f, wherein the coils 610a-f are arranged in a circle. Each coil 610a-f may comprise a wire that is substantially in the shape of a sector of a circle, also referred to as a trapezoid. Thus, the wires of the coils 610a-f may include a single loop in the shape of a trapezoid, or may include multiple loops in the shape of a trapezoid. The coils 610a-f may be configured to generate a magnetic field or to receive a magnetic field. Further, they may be configured to change their mode of operation from generating a magnetic field to receiving a magnetic field, and vice versa. For example, in a first instance in time, the coils 610a and 610d may be receive coils, while the remaining coils 610b/c/e/f are transmit coils. The coils 610a and 610d may form a differential pair and output a differential signal. In another example of time, the coils 610b and 610e may be receive coils, while the remaining coils 610a/c/d/f are transmit coils. In this time example, coils 610b and 610e may form a differential pair and output a differential signal. In yet another example of time, the coils 610c and 610f may be receive coils, while the remaining coils 610a/b/d/e are transmit coils. In this time example, coils 610c and 610f may form a differential pair and output a differential signal. The different differential signals may then be combined to determine the location of the target. It is clear that any arbitrary cyclic shift can be performed even though a clockwise cyclic shift of the receiving coil is described herein. Furthermore, even though forming differential pairs and outputting differential signals are described, it will be clear to those skilled in the art that each coil 510a-f may output signals individually. Furthermore, it is clear that all coils 610a-f can independently change their operation mode from a receive mode to a transmit mode.

Although the drawings depicted herein refer to explicit coil arrangements and coil shapes, it will be clear to those skilled in the art that further arrangements and shapes are possible. Any shape of coil that maintains rotational symmetry with respect to the number of receive coils is possible. For example, a three coil embodiment may include a substantially triangular coil shape, and a five coil embodiment may include a substantially pentagonal coil shape.

It is also clear to the person skilled in the art that a suitable number of receiving coils may be associated with a shape or form an object whose position should be sensed. For example, embodiments of a rotational sensor including three receive coils may be sensitive to sensing target positions from 0 ° to 180 °. In another embodiment of the rotation sensor, an arrangement comprising five receiving coils may be sensitive for sensing a target position from 0 ° to 360 °. In general, using more receive coils may provide lower induced voltage amplitudes, and processing of a larger number of signals received from the receive coils may be more complex.

What has been described above includes examples of one or more embodiments. It is, of course, not possible to describe every conceivable combination of components, assemblies or methodologies for purposes of describing the aforementioned embodiments, but one of ordinary skill in the art may recognize that many further combinations and permutations of various embodiments are possible. Accordingly, the described embodiments are intended to embrace all such alterations, modifications and variations that fall within the spirit and scope of the appended claims.