ELECTRONIC DEVICE CONTAINING AN ELECTRICAL CURRENT SENSOR

Abstract

According to one aspect, an electronic device is proposed comprising a support substrate (SUP) and an electronic chip (CHP) assembled to the support substrate (SUP). The support substrate (SUP) includes an electric current sensor (SENS) comprising a planar transformer (TRSF) configured to: - detect a magnetic field (FLD) generated by an electric current to be monitored, and - deliver a voltage induced by this magnetic field in the planar transformer (TRSF) to said electronic chip (CHP). Figure for the abbreviation: Figure 1

Description

Title of the invention: ELECTRONIC DEVICE COMPRISING AN ELECTRICAL CURRENT SENSOR

[0001] Embedding and implementation methods relate to electric current sensors.

[0002] Electric current sensors are devices used to measure the intensity of electric current flowing in an electrically conductive wire or in an electrically conductive track.

[0003] There is an interest in manufacturing suitable current sensors to monitor an electric current flowing on a printed circuit board.

[0004] A dedicated component, mounted on the printed circuit board, can be used as a current sensor. This sensor is then configured to generate a signal based on the intensity of the monitored current. This signal is then transmitted to a processing component, for example, a microcontroller. For instance, a Rogowski coil can be used as a current sensor in a dedicated component.

[0005] The use of such a current sensor requires a printed circuit board large enough to integrate the current sensor. Furthermore, in some cases, the conductive traces carrying the current to be monitored, or the current carrying the signal from the sensor translating the measured current, pass through the printed circuit board and may be exposed to external magnetic radiation, which can reduce the performance of the electrical current sensor.

[0006] There is therefore a need to propose a solution to simplify the use of an electric current sensor to monitor a current carried in a printed circuit board.

[0007] According to one aspect, an electronic device is proposed comprising a support substrate and an electronic chip assembled to the support substrate, the support substrate comprising an electric current sensor including a planar transformer configured to: - to capture a magnetic field generated by an electric current to be monitored, and - deliver a voltage induced by this magnetic field to said electronic chip.

[0008] Such an electronic device therefore incorporates a current sensor configured to monitor an electric current. In particular, the current sensor is integrated into a substrate supporting an electronic chip configured to process the signal generated by this current sensor. Such a current sensor has the advantage of avoiding the use of an electric current sensor formed within an electronic component. independent. Such an electronic device therefore makes it possible to reduce the cost of using a current sensor.

[0009] Furthermore, in such an electronic device, the current sensor is located close to the electronic chip that processes the signal generated by the sensor. Thus, the signal generated by the current sensor travels a shorter distance to reach the electronic chip. This helps to reduce disturbances on this signal.

[0010] In an advantageous embodiment, the planar transformer comprises at least one electrically conductive winding. The transformer may comprise several electrically conductive windings. In this case, the windings may extend in the same plane.

[0011] Advantageously, the supporting substrate includes an electrically conductive track carrying the current to be monitored.

[0012] In an advantageous embodiment, the conductive track carrying the current to be monitored extends in the support substrate between the windings of the planar transformer.

[0013] Advantageously, the electric current sensor includes at least one ferromagnetic element in the support substrate.

[0014] Said at least one ferromagnetic element makes it possible to confine and concentrate the magnetic field B generated by the current to be monitored. In this way, the current induced in the windings of the sensor is greater.

[0015] Preferably, the electric current sensor includes a ferromagnetic element between the planar transformer and the electronic chip.

[0016] This ferromagnetic element limits electromagnetic interactions with the electronic chip of the electronic device. In particular, the ferromagnetic element isolates the electronic chip from the magnetic field H generated by the current being monitored flowing in the conductive track.

[0017] In an advantageous embodiment, the electric current sensor also includes a ferromagnetic element under the planar transformer.

[0018] Advantageously, the device further includes a matrix of connection elements under the supporting substrate, the matrix of connection elements being configured to be assembled to a printed circuit board.

[0019] Preferably, the planar transformer is configured to be placed opposite a conductive track carrying the current to be monitored on the printed circuit board.

[0020] According to another aspect, a system is proposed comprising: - a printed circuit board, and - an electronic device as defined above, assembled to the printed circuit board.

[0021] Advantageously, the printed circuit board includes a track configured to carry an electric current, and said electronic device is configured to monitor this electric current.

[0022] According to another aspect, a method for manufacturing an electronic device is proposed, comprising obtaining a support substrate and assembling an electronic chip onto the support substrate, the support substrate comprising an electric current sensor including a planar transformer configured for: - to capture a magnetic field generated by an electric current to be monitored, and - to deliver a voltage induced by this magnetic field to said electronic chip.

[0023] In an advantageous embodiment, the planar transformer comprises at least one electrically conductive winding.

[0024] Advantageously, the supporting substrate includes an electrically conductive track carrying the current to be monitored.

[0025] In an advantageous embodiment, the conductive track carrying the current to be monitored extends in the support substrate between the windings of the planar transformer.

[0026] Advantageously, the electric current sensor includes at least one ferromagnetic element in the support substrate.

[0027] Preferably, the electric current sensor includes a ferromagnetic element between the planar transformer and the electronic chip.

[0028] In an advantageous embodiment, the electric current sensor also includes a ferromagnetic element under the planar transformer.

[0029] Advantageously, the method further includes obtaining a matrix of connection elements under the supporting substrate, the matrix of connection elements being configured to be assembled to a printed circuit board.

[0030] Preferably, the planar transformer is configured to be placed opposite a conductive track carrying the current to be monitored on the printed circuit board.

[0031] According to another aspect, a method for manufacturing an electronic device is proposed, comprising the formation of a support substrate and the assembly of an electronic chip onto the support substrate, the formation of the support substrate comprising the formation of an electric current sensor including a planar transformer configured for: - to capture a magnetic field generated by an electric current to be monitored, and - to deliver a voltage induced by this magnetic field to said electronic chip.

[0032] In an advantageous embodiment, the formation of the electric current sensor includes the formation of at least one electrically conductive winding.

[0033] Advantageously, the formation of the support substrate includes the formation of an electrically conductive track carrying the current to be monitored.

[0034] In an advantageous embodiment, the conductive track carrying the current to be monitored extends in the supporting substrate between the windings of the planar transformer.

[0035] Preferably, the formation of the electric current sensor includes the formation of at least one ferromagnetic element in the supporting substrate.

[0036] Advantageously, the formation of the electric current sensor includes the formation of a ferromagnetic element between the planar transformer and the electronic chip.

[0037] Preferably, the formation of the electric current sensor also includes the formation of a ferromagnetic element under the planar transformer.

[0038] Advantageously, the method further comprises forming a matrix of connecting elements under the supporting substrate, the matrix of connecting elements being configured to be assembled to a printed circuit board.

[0039] In an advantageous implementation mode, the planar transformer is formed so that it can be placed opposite a conductive track carrying the current to be monitored on the printed circuit board.

[0040] Other advantages and features of the invention will become apparent upon examination of the detailed description of embodiments, which are by no means limiting, and the accompanying drawings in which:

[0041] [Fig.1]

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[0055] [Fig. 15] illustrate embodiments and implementations of the invention.

[0056] Figure 1 illustrates a first embodiment of a longitudinal sectional view of a system comprising an electronic device DIS and a printed circuit board BRD.

[0057] The electronic device DIS is configured to be connected to the printed circuit board BRD. The electronic device includes an electrical current sensor SENS, formed in a support substrate SUP, and a CHP (chip-mounted) electronic die. The electronic device DIS may include other surface-mounted electronic components COMP, that is, components assembled to the support substrate SUP. For example, the electronic device DIS is a microcontroller.

[0058] The SUP support substrate is a laminated substrate that integrates the SENS electric current sensor.

[0059] The SUP support substrate is in the form of a plate having an upper principal face FSUP, defining the top of the support substrate, and a lower principal face FINE, defining the bottom of the SUP support substrate. The CHP electronic chip and the COMP electronic components are assembled to the upper principal face FSUP of the support substrate.

[0060] The DIS electronic device also features a COM connection element matrix assembled to the underside of the SUP support substrate. This COM connection element matrix is ​​configured to be assembled to the BRD printed circuit board. The connection element matrix then allows the support substrate to be electrically connected to the printed circuit board.

[0061] In this embodiment, the COM connection element matrix is ​​a ball matrix (also designated by the abbreviation "BGA", in English "Bail Grid Array"). However, alternatively, it is possible to provide a COM connection element matrix of the pad matrix type (also designated by the abbreviation "LGA", in English "Land Grid Array").

[0062] The SENS electric current sensor is configured to detect an electric current flowing in an electrically conductive track CTRC. The electric current to be monitored is an alternating current. The electric current to be monitored could, for example, be a current used to control an electric motor (not shown). Other applications are possible. For example, it is possible to use such an electronic device DIS in 5G or LiDAR applications to monitor a current used to form an electromagnetic beam.

[0063] In the embodiment illustrated in [Fig. 1], the electric current to be monitored flows in a conductive track CTRC integrated into the support substrate SUP. This current to be monitored may originate from a track (not shown) of the circuit board. printed BRD and be transmitted to the substrate track via the matrix of connecting elements.

[0064] When the electric current to be monitored flows through the conductive track CTRC, this electric current generates a magnetic field FLD. This magnetic field FLD induces an electric current in the electric current sensor SENS. The sensor is configured to output a signal from the induced electric current. The current sensor is electrically connected to the electronic chip CHP via an interconnect circuit INT integrated into the support substrate SUP. In this way, the signal emitted by the current sensor SENS can be transmitted to the electronic chip CHP for processing. For example, the electronic chip CHP can be configured to adjust the intensity of the current to be monitored according to the voltage induced in the current sensor SENS. For example, the electronic chip CHP can adjust the current to be monitored to adapt the control of an electric motor.

[0065] The SENS current sensor includes a planar transformer TRSF. In particular, the planar transformer TRSF includes at least one electrically conductive winding. In the embodiment illustrated in Figures 1 and 2, the planar transformer TRSF has two electrically conductive windings ENRL1 and ENRL2. Each winding ENRL1 and ENRL2 is formed from a conductive track or a spirally wound conductive wire. The conductive track carrying the electric current to be monitored extends between the two windings.

[0066] The two windings ENRL1, ENRL2 are located in the same plane parallel to the main faces FSUP, FINF of the support substrate SUP. [Fig. 2] illustrates a cross-sectional view of the SENS electric current sensor along this parallel plane.

[0067] The two windings ENRL1, ENRL2 are also spaced apart from each other by a distance of between 20 micrometers and 200 micrometers.

[0068] Each winding ENRL1, ENRL2 has a thickness between 10 micrometers and 50 micrometers. Each winding ENRL1, ENRL2 has a width between 50 micrometers and 10 millimeters.

[0069] Each winding ENRL1, ENRL2 has a first end EXT1 connected to an electrically conductive VCO via the interconnect circuit INT, allowing this winding to be electrically connected to the electronic chip. Each winding also has a second end EXT2 connected to the CHP electronic chip. The CHP electronic chip is then configured to observe a voltage difference between the two ends of each winding.

[0070] In this way, the voltage induced at the output of each winding ENRL1, ENRL2 from the magnetic field produced by the CTRC track carrying the current to be monitored can be transmitted to the electronic chip CHP.

[0071] Each winding ENRL1, ENRL2 can be made of a metallic material such as copper.

[0072] The shape of each winding ENRL1, ENRL2 can be arbitrary. It can, for example, be rectangular as schematically illustrated in [Fig.2] or circular.

[0073] By way of example, the length of each winding ENRL1, ENRL2 can be between 200 micrometers and 50 millimeters, with a number of turns between one and one hundred.

[0074] The windings ENRL1, ENRL2 are arranged in a layer of dielectric material DIEL of the SENS electric current sensor. The layer of dielectric material DIEL has a thickness of between 10 micrometers and 100 micrometers.

[0075] The SENS electric current sensor comprises at least one ferromagnetic element FMG. This at least one ferromagnetic element FMG confines and concentrates the magnetic field B generated by the current being monitored. As a result, the current induced in the windings ENRL1, ENRL2 of the SENS sensor is greater.

[0076] In the embodiment illustrated in [Fig. 1], the electric current sensor SENS comprises two ferromagnetic elements FMGS, FMGI located on each side of the dielectric material layer.

[0077] In particular, the SENS electric current sensor includes an upper ferromagnetic element FMGS extending over the upper face of the dielectric layer DIEL of the SENS current sensor. This upper ferromagnetic element FMGS limits electromagnetic interactions with the electronic chip CHP of the DIS electronic device. In particular, the upper ferromagnetic element FMGS isolates the electronic chip CHP from the magnetic field H generated by the current to be monitored flowing in the conductive track CTRC.

[0078] The upper ferromagnetic element FMGS has an opening for each via conductor connecting the windings to the interconnecting circuit. Thus, each opening is traversed by a via conductor.

[0079] Each ferromagnetic FMG element has a thickness between 10 micrometers and one millimeter.

[0080] For example, each ferromagnetic FMG element can be formed from a ferromagnetic resin or a ferromagnetic film. This hardened resin can comprise a dielectric material such as a polymer, for example nylon 6, nylon 12, or a polyamide including a magnetic material, for example strontium ferrite (Sr), a neodymium-iron-boron alloy (NdFeB), a CoZrO alloy which exhibits high-frequency performance suitable for radio frequency applications, a cobalt-nickel-iron (CoNiFe) alloy, or amorphous iron-cobalt alloys, and any combination of at least some of the elements mentioned above.

[0081] In the embodiment illustrated in [Fig. 1], the electrical current sensor SENS is located midway through the thickness of the support substrate SUP. However, it is possible to place the electrical current sensor SENS at other heights within the thickness of the support substrate SUP. For example, it is possible to place the electrical current sensor SENS at the top of the support substrate SUP, as illustrated in [Fig. 3], or at the bottom of the support substrate SUP (not shown).

[0082] Furthermore, the SENS electric current sensor can extend over the entire width and length of the SUP support substrate. However, it is possible to provide a SENS electric current sensor extending only partially over the width and length of the support substrate, as illustrated in [Fig. 4].

[0083] Such an electronic DIS device makes it possible to avoid using an electric current sensor formed in a separate electronic component. Such an electronic DIS device therefore reduces the cost of using an electric current sensor.

[0084] Furthermore, in such an electronic DIS device, the SENS electric current sensor is located close to the CHP electronic chip that processes the signal transmitted by the SENS electric current sensor. Thus, the signal from the SENS electric current sensor travels a shorter distance to reach the CHP electronic chip. This helps to reduce interference on this signal.

[0085] Figure 5 illustrates another embodiment of an electronic DIS device. The electronic DIS device can be connected to the printed circuit board via a COM connection element matrix of the pad matrix type. However, alternatively, a COM connection element matrix of the bead matrix type can be provided.

[0086] In the illustrated embodiment, the CTRC conductive track, carrying the electric current to be monitored, is located outside the SUP support substrate of the DIS electronic device. In particular, the CTRC conductive track extends directly onto the BRD printed circuit board.

[0087] In this embodiment, the DIS electronic device includes ASM assembly elements configured to assemble the SUP support substrate to the BRD printed circuit board, creating a gap between the SUP support substrate and the BRD printed circuit board. In this way, the SENS electric current sensor can be positioned opposite the CTRC conductive track extending into the gap between the BRD printed circuit board and the SUP support substrate.

[0088] The SENS electric current sensor is then placed at the bottom of the SUP support substrate. Furthermore, the space between the SUP support substrate and the printed circuit board BRD is sufficiently reduced to allow the magnetic field generated by the electric current being monitored to reach the windings of the SENS sensor.

[0089] In the embodiment illustrated in [Fig. 5], the SENS electric current sensor has a single ferromagnetic element FMGS located above the dielectric layer DIEL. The SENS electric current sensor does not have a ferromagnetic element below the dielectric layer DIEL. The dielectric layer DIEL, which incorporates the windings of the SENS electric current sensor, is then located at the bottom of the support substrate SUP.

[0090] Alternatively, in the embodiment illustrated in [Fig. 6], the SENS electric current sensor comprises two ferromagnetic elements FMGS, FMGI on either side of the dielectric layer DIEL, which incorporates the windings of the SENS sensor. The ferromagnetic element FMGI located beneath the dielectric layer is positioned at the bottom of the SUP support substrate and has an OPN aperture facing the CTRC conductive track carrying the electric current to be monitored. This OPN aperture allows the magnetic field FLD generated by the electric current to reach the ENRL1, ENRL2 windings of the SENS sensor.

[0091] The embodiments illustrated in Figures 5 and 6 have the advantage of avoiding the need to route the current to be monitored through a conductive trace of the SUP substrate. Thus, due to the distance between the electronic device DIS and the conductive trace carrying the current to be monitored, the electronic device is less affected by Joule heating of the CTRC conductive trace. Consequently, it is possible to monitor a higher nominal current.

[0092] Figure 6 illustrates an implementation method for manufacturing an electronic DIS device as described above.

[0093] The manufacturing process includes a formation 21 of the electrical current sensor SENS during a formation of the support substrate SUP.

[0094] The formation of the electric current sensor SENS includes a formation 21-1 of a layer of electrical material DIEL and a formation 21-2 of the windings ENRL1, ENRL2 of the electric current sensor SENS.

[0095] In particular, the method comprises forming a first layer of the dielectric material layer DIEL. The result of forming this first layer of the dielectric material notch is illustrated in [Fig. 8]. The method then comprises deposition of the windings ENRL1, ENRL2 of the electrical current sensor SENS and optionally deposition of a conductive track carrying the current to be monitored in the case of manufacturing an electronic device DIS as described in relation to Figures 1 to 4, in which the conductive track extends into the support substrate SUP. The result of this deposition is illustrated in [Fig. 9]. The method then comprises deposition of a second layer of DIEL dielectric material to form the DIEL dielectric material layer. The result of this deposition is illustrated in [Fig. 10].

[0096] The process then comprises a deposition 21-3 of said at least one ferromagnetic element FMG onto the layer of electrical material. In particular, the process comprises a deposition of only an upper ferromagnetic element, or alternatively, the deposition of an upper ferromagnetic element and a lower ferromagnetic element. For example, the deposition of a ferromagnetic element is carried out by depositing a ferromagnetic film or a ferromagnetic resin. Figure 11 illustrates an example of the result of such a deposition of ferromagnetic elements FMGS, FMGI.

[0097] The process then comprises forming 22 an interconnection circuit INT of the supporting substrate and conductive vias VCO for connecting the windings ENRL1, ENRL2 to the interconnection circuit. Figure 12 illustrates an example of the result of forming conductive vias. To form these conductive vias, openings are made in the upper ferromagnetic element, and then a layer of dielectric material is deposited in these openings. Next, an opening is made in each layer of dielectric material, and then conductive vias are deposited in these openings. The result of forming the interconnection circuit is illustrated in Figure 13.

[0098] The method then comprises forming 23 a matrix of COM connection elements for assembling the electronic device DIS to a printed circuit board BRD. Figure 14 illustrates an example of the result of forming a matrix of COM connection elements.

[0099] The method then comprises assembling 24 a CHP electronic chip onto the SUP support substrate so as to connect the CHP electronic chip to the INT interconnect circuit. Figure 15 illustrates an example of the result of assembling a CHP electronic chip onto the SUP support substrate.

[0100] The method may also include an assembly of 25 other COMP components to the SUP support substrate.

[0101] Once manufactured, the electronic device can be mounted on a printed circuit board. In the case of an electronic device such as those illustrated in Figures 5 and 6, the printed circuit board has a conductive trace carrying the current to be monitored. The electronic device is then placed above this conductive trace.

[0102] Of course, the present invention is susceptible to various variations and modifications which will become apparent to those skilled in the art. For example, the electric current sensor may not include a layer of dielectric material DIEL. Indeed, the conductivity is relatively low, so a layer of dielectric material DIEL may not be necessary.

Claims

Demands

1. Electronic device comprising a support substrate (SUP) and an electronic chip (CHP) assembled to the support substrate (SUP), the support substrate (SUP) having an electric current sensor (SENS) comprising a planar transformer (TRSF) configured to: - capture a magnetic field (FLD) generated by an electric current to be monitored, and - deliver a voltage induced by this magnetic field to said electronic chip (CHP).

2. Device according to claim 1, wherein the planar transformer (TRSF) comprises at least one electrically conductive winding (ENRL1, ENRL2).

3. Device according to any one of claims 1 or 2, wherein the support substrate (SUP) has an electrically conductive track (CTRC) carrying the current to be monitored.

4. Device according to any one of claims 1 to 3, wherein the electric current sensor comprises at least one ferromagnetic element (FMG) in the support substrate (SUP).

5. Device according to any one of claims 4, wherein the electric current sensor (SENS) comprises a ferromagnetic element (FMGS) between the planar transformer (TRSF) and the electronic chip (CHP).

6. Device according to claim 5, wherein the electric current sensor (SENS) also includes a ferromagnetic element (FMGI) under the planar transformer (TRSF).

7. Device according to any one of claims 1 to 6, further comprising a matrix of connecting elements (COM) under the support substrate (SUP), the matrix of connecting elements being configured to be assembled to a printed circuit board (BRD).

8. Device according to claim 7 taken in combination with claim 3, wherein the planar transformer (TRSF) is configured to be placed opposite a conductive trace (CTRC) carrying the current to be monitored on the printed circuit board (BRD).

9. System comprising: - a printed circuit board having a track configured to carry an electric current, and - an electronic device according to any one of claims 1 to 8, assembled to the printed circuit board and configured to monitor said electric current.

10. A method for manufacturing an electronic device, comprising obtaining a support substrate (SUP) and assembling an electronic chip (CHP) to the support substrate (SUP), the support substrate (SUP) comprising an electric current sensor (SENS) comprising a planar transformer (TRSF) configured to: - capture a magnetic field (FLD) generated by an electric current to be monitored, and - deliver a voltage induced by this magnetic field to said electronic chip (CHP).

11. A manufacturing method according to claim 10, wherein the electric current sensor (SENS) comprises at least one electrically conductive winding (ENRL1, ENRL2).

12. A method according to any one of claims 10 or 11, wherein the support substrate (SUP) comprises an electrically conductive track (CTRC) carrying the current to be monitored.

13. Method according to any one of claims 10 to 12, wherein the electric current sensor comprises at least one ferromagnetic element (FMG) in the support substrate (SUP).

14. A method according to any one of claims 13, wherein the electric current sensor (SENS) comprises a ferromagnetic element (FMGS) between the planar transformer (TRSF) and the electronic chip (CHP).

15. Method according to claim 14, wherein the electric current sensor (SENS) also includes a ferromagnetic element (FMGI) under the planar transformer (TRSF).

16. A method according to any one of claims 10 to 15, further comprising obtaining a matrix of connecting elements (COM) under the support substrate (SUP), the matrix of connecting elements being configured to be assembled to a printed circuit board (BRD).

17. A method according to claim 16 taken in combination with claim 12, wherein the planar transformer (TRSF) is configured to be placed opposite a conductive track (CTRC) carrying the current to be monitored on the printed circuit board (BRD).

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