FR3090991A1 - INDUCTIVE SET - Google Patents

Abstract

Inductive assembly comprising first conductive elements (E1) and a substrate (2) comprising second conductive elements, each first conductive element (E1) having a U shape containing in a plane and extending orthogonally to the substrate (2), each branch of the first conductive elements (E1) being electrically connected to a second conductive element distinct from that to which the other branch is connected. Thus turns are formed by the first conductive elements (E1) and the second conductive elements. Figure for the abstract: Figure 1.

Description

Description

Title of the invention: INDUCTIVE SET

TECHNICAL FIELD AND PRIOR ART

The present invention relates to an inductive assembly and to its production method.

Inductive devices are for example used in very high frequency converters and switching power supplies for power electronics and in high frequency transformers.

An inductive device is a device comprising an electric circuit forming a winding so that, when an electric current flows in the electric circuit, a magnetic flux appears inside the winding. The inductive device may include a core disposed in an area where the coil creates the magnetic flux.

Inductive devices or coils are generally made by winding a wire conductor around a core.

However, when the current flowing in the conductor is a high frequency alternating current, a skin effect appears, ie the current tends to flow only on the outer periphery of the wire, a tendency which increases with the increase of frequency.

Windings with flat conductors, i.e. having a small thickness compared to their width can then be used to alleviate the appearance of this phenomenon.

However, the production for example of toroids with a flat conductor is complex.

One solution is to produce such a winding with the techniques of microelectronics, i.e. by implementing layers, in which the conductors are produced by conductive tracks in different planes and are connected to each other via via. However, there is a phenomenon of proximity between the conductors and the appearance of stray capacitance.

Document US 9754714 describes an exemplary embodiment of an inductive device comprising flat conductors. The device comprises a first substrate provided with a face in which an annular recess is formed in which the first flat conductive elements are arranged flat next to each other, each first flat conductive element is disposed on the two annular edges and the bottom of the recess and has two tabs at each of its ends flat on the face of the first substrate. The device comprises a second substrate comprising second electrical conductors arranged so as to form, with the first conductive elements, windings. A core is arranged in the annular recess inside the first conductive elements.

We are trying to increase the number of turns per unit area. In addition, a proximity effect between the first elements may appear.

Statement of the invention

It is therefore an object of the present invention to provide an inductive assembly having a reduced skin effect and also a reduced proximity effect, and in which the number of windings achievable is increased compared to the devices. the state of the art.

The aim stated above is achieved by an inductive device comprising at least a first conductive element and a substrate with at least a second conductive element. The at least first conductive element extends in at least one plane different from the substrate, said at least one first conductive element being electrically connected to at least one second conductive element, said at least one first conductive element being configured so that its grip the ground is reduced compared to the devices of the prior art.

For this, the first conductive element comprises two large surface areas separated by a small thickness and forming a conductive path comprising first and second portions each connected to a second conductive element and a third connection portion between the first and second portions , the third portion being oriented so that the current lines are at different distances from the substrate by considering a transverse direction of the faces with respect to the flow of current.

In other words, the first conductive element or elements have a shape such that, while having the same section of current flow, their projection onto the substrate is significantly reduced.

Thus, the number of first conductive elements which can be mounted on the substrate is increased, as well as the number of turns formed.

The device according to the invention is of easier manufacture compared to the inductive devices of the state of the art, in particular those having a closed contour, such as toroidal devices.

According to the invention, the first conductive elements extend mainly transversely to the substrate, which significantly reduces the footprint of each first conductive element. The number of windings achievable is significantly increased.

Part of the inductive circuit is made in the substrate and another part is made above the substrate and can implement several electrical conductors above the substrate arranged side by side. In an advantageous example, the first conductive elements are planar and are orthogonal to the substrate, their projection is reduced to the thickness of the first conductive element

In an exemplary embodiment, the first conductive elements have U-shapes, the free ends of the U being connected to the second conductors.

For example, the first conductive elements can be cut from metal plates, for example from copper plates, or be produced separately in the form of a printed circuit, for example by depositing at least one conductive line on an insulating substrate, for example made of epoxy.

The present invention is particularly advantageous for producing inductive devices with closed contours, such as toric devices which are very difficult to achieve by conventional winding techniques. The present invention is also very advantageous for producing inductive devices of the E-I type, since it avoids using a multi-part core in which the presence of an air gap cannot be avoided.

The present invention also makes it easy to simultaneously produce several windings, for example to produce a current or voltage transformer.

Alternatively, first conductive elements are connected to the substrate on the two faces of the substrate each comprising second conductive elements.

The present invention has the advantage of making it possible to produce inductive devices on printed circuit boards which can integrate other functions. Thus, the invention achieves a high level of integration.

The present invention therefore relates to an inductive assembly comprising at least n first conductive elements and a substrate comprising at least n second conductive elements, n being an integer greater than or equal to 1, each first conductive element extending at least partly in a plane different from the substrate, and comprising a first end and a second end connected by an electrically conductive path, the conductive path comprising a first portion electrically connected to one of the second conductive elements by the first end, and a second connected portion electrically to the other of said second conductive elements by the second end, and at least a third connection portion between the first portion and the second portion, the conductive path also comprising two faces connected by edges, said faces having a very large surface relative to that of the edges so that the conductive path pres ente a thin thickness, the faces having a transverse dimension relative to the direction of circulation of the electric current in said conductive path. The first, second and third portions are oriented so that the current lines flowing in the third portion are located at different distances from the substrate in the transverse direction of the faces.

Preferably, n is greater than or equal to 2, and a first portion of an electrically conductive element is electrically connected to one of the second conductive elements by the first end, and a second portion of the electrically conductive element is connected electrically to the other of said second conductive elements by the second end.

Preferably, the transverse dimension is substantially constant along the conductive path between the first end and the second end.

In an exemplary embodiment, each first conductive element is contained in one or more planes, each plane being orthogonal to the substrate. In an advantageous example, each first conducting element is contained entirely in a plane distinct from the planes containing the other first conducting elements.

In one configuration, the n first conductive elements and the n second conductive elements are electrically connected forming a single inductive device.

In another configuration, at least a first part of the first conductive elements and second conductive elements are electrically connected to each other and a second part of the first conductive elements and second conductive elements are electrically connected to each other and electrically isolated from the first part first conductive elements and second conductive elements, forming two inductive devices.

In an exemplary embodiment, the first conductive elements have the shape of a U, the first and second portions forming the branches of the U and the third portion forms the bottom of the U.

The first and second ends may include at least one mechanical and / or electrical connection tab. In an advantageous example, the substrate has holes in which the connection tabs are inserted.

Each connection tab can be held in an orifice by mechanical cooperation with the wall of the orifice and / or by a solder.

In another embodiment, the assembly includes first conductive elements on one face of the substrate and first conductive elements on the other face of the substrate.

For example, the first n conductive elements and the second second conductive elements are distributed radially so as to form one or more toroidal inductive devices.

The second conductive elements can be distributed in several substantially parallel planes of the substrate.

According to an exemplary embodiment, the first conductive elements are cut from a plate of electrically conductive material. According to another example, each first conductive element comprises a substrate made of electrically insulating material and a track made of electrically conductive material between the first and second ends and forming the conductive path.

The substrate is advantageously a printed circuit.

The first conductive elements are held integral with each other by an overmolded electrical insulating material.

The present invention also relates to an electrical transformer comprising at least one inductive assembly according to the invention. The first part of the first conductive elements and second conductive elements form a primary and the second part of the first conductive elements and second conductive elements form a secondary.

The present invention also relates to a method of manufacturing an inductive assembly according to the invention, comprising:

- the manufacture of n first conductive elements,

- the manufacture of the substrate with the n second conductive elements, the mounting of the n first conductive elements, comprising:

- the mechanical fixing of the n first conductive elements to the substrate, - the electrical connection of each first conductive element to two second conductive elements.

The first n conductive elements can be manufactured by cutting a plate of electrically conductive material, or the first n conductive elements are manufactured from a printed circuit.

During assembly, connection tabs of the first conductive elements are for example inserted in the orifices of the substrate.

In an exemplary embodiment, the mechanical fixing and the electrical connection are made by soldering connection tabs of the first conductive elements to and / or in the second conductive elements and / or by inserting the tabs of the orifices of the substrate.

Prior to mounting, the first n conductive elements may be fixed relative to each other and then be simultaneously mounted on the substrate.

Preferably, the first n conductive elements are mounted in a tool.

In an exemplary embodiment, an electrical insulating material is overmolded on the first conductive elements and are held stationary with respect to each other.

Brief description of the drawings

The present invention will be better understood on the basis of the description which follows and the attached drawings in which:

[Fig-1] is a perspective view of an exemplary embodiment of an inductive device according to the invention,

[FIG. 2A] is a side view of an exemplary embodiment of a first conductive element,

[Fig.2A ’] is a perspective view of the first conductive element of FIG. 2A,

[Fig.2B] is a side view of another embodiment of a first conductive element,

[Fig.2C] is a side view of another embodiment of a first conductive element,

[Fig.2D] is a perspective view of another embodiment of a first conductive element connected to the substrate,

[Fig. 3] is a front view of another embodiment of a first conductive element produced in the form of a printed circuit,

[Fig.4] is a top view of the substrate of the device of Figure 1 shown alone, supporting the second conductive elements,

[Fig.5] is a schematic representation of a detailed view of the device of Figure 1,

[Fig.6A] is a perspective view of another example of a first conductive element extending in several planes,

[Fig.6B] is a top view of several first conductive elements of FIG. 6A,

[Fig.7A] is a perspective view of another example of a first conductive element extending in several planes,

[Fig.7B] is a perspective view of several first conductive elements of FIG. 7A,

[Fig.8] is a top view of an example of a substrate allowing the production of two inductive devices using conductive elements of identical or similar shape to those of the device of Figure 1,

[Fig.9] is a perspective view of an example of an inductive device according to the invention comprising a large number of turns.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

In the description, the term "conductor" means "electrical conductor".

In the present application, the term "substrate" means a planar or substantially planar element comprising a part made of electrical insulating material and several conductive tracks which extend at least in the plane of the substrate. The substrate may include conductive tracks in several levels of the substrate, preferably parallel to each other and which can be connected by vias. Typically a substrate is manufactured by microelectronics techniques. A printed circuit or PCB (Printed Circuit Board in English terminology) is an example of a substrate according to the invention.

In Figure 1, we can see an embodiment of an inductive device according to the invention comprising a substrate 2, a plurality of first electrical conductive elements El and a core 4 disposed in the space delimited by the substrate 2 and the first conducting elements El.

In this example, the substrate extends in the XY plane and the first conductive elements El extend in planes orthogonal to the XY plane and containing the direction Z.

In this example, the substrate 2 has the shape of a disc and the core 4 has the shape of a ring with an outside diameter less than the diameter of the substrate, so as to provide an outer annular rim on the substrate to fix a free end of the first conductive elements El.

The first conductive elements El are fixed on the substrate 2 which forms both a mechanical support and an electrical connector.

In Figure 2A, we can see an example of the first conductive element El shown alone. In this example, the first conductive element El is contained in a plane and has a U shape, the two free ends of which El. 1, El.2 are intended to be fixed to the substrate 6. The branches are designated by Bl, B2 and the bottom 15 of the U connecting the two branches.

The first conductive element comprises a conductive path CC connecting the two ends ELI and El.2. The conductive path CC has a transverse dimension L which is perpendicular to the direction of current flow symbolized by the current lines II, 12, 13 in FIG. 5. Preferably, the transverse dimension L is substantially constant along the conductive path between the first and the second end.

Preferably, the conductive path CC of each first conductive element E1 and the conductive path of each second conductive element E2 have near or equal current flow sections.

In FIG. 2A ', we can see the conductive path CC comprising two large faces E connected by a flange R. The two faces are separated by a small distance e from the other dimensions of the first conductive element and which corresponds to the thickness of the conductive path.

The first conductive element El has a height h. In this example, the two branches BI and B2 of the U have the same height h.

The bottom of the U or connection portion 15 has a dimension 1 between the two branches B2, B2.

Preferably e / L <1. Also preferably, L> 0.5 mm, 1> 1 mm and 10 pm <e <0.5 mm.

For simplicity, the first conductive elements El will be designated "connection bridges" in the following description.

The connection bridge El of Figure 2A is made entirely of electrically conductive material, for example by cutting from a sheet of conductive material, for example copper. Thus the conductive path forms the connection bridge.

The thickness of the plate of electrically conductive material is sufficient for the first conductive elements to be self-supporting.

In the example of FIG. 2A, the free ends ELI and E1.2 each comprise two conductive tabs 6 which are intended to come to connect the first conductive element El to second conductors E2 formed in, or on, the substrate 2. It will be understood that the number of legs 6 is not limiting.

In Figure 4, we can see an example of substrate 2 on which the El connection bridges are mounted. The substrate has orifices O for the insertion of the tabs 6 of the first conductive elements. The orifices O have shapes adapted to the shape of the legs, they are for example circular for cylindrical legs with circular section or of oblong shape for blade-shaped legs.

The first conductive elements can be secured to the substrate for example by soldering or by insertion, preferably cold.

The mechanical connection and the electrical connection can be made by the same means or different means. For example, we can consider a mechanical connection by embedding and an electrical connection by solder

In Figure 4, the second electrical conductors E2 formed by conductive tracks located on at least one face of the substrate 2. The second conductors E2 extend substantially radially on the substrate 2, so that a free end d 'a connection bridge El located radially outside, and the free end of another adjacent connection bridge El located radially inside can connect to the same second conductor E2 and thus form a winding.

A free end of a first conductive element El is electrically connected to a second conductive element E2, which is distinct from that to which the other free end of the same first conductive element is connected, so as to electrically connect all of the first conductive elements in series and to be formed with the second conductors of the windings.

In Figure 5, we can see shown a detail of the device of Figure 1 showing the electrical connections between the first and second conductors.

Let us designate El and El 'the first two directly adjacent conductive elements, a free end El.l of the first conductive element El located radially on the outside is electrically connected to the second conductor E2, a free end El.l' of the first element conductor El 'located radially inside is electrically connected to the second conductor E2. Current lines II, 12, 13 are shown in FIG. 5. It can be seen that current line II is closer to the substrate than lines 12 and 13.

The first conductive elements El are for example produced by cutting from a plate of electrically conductive material, for example a copper plate. For example, it is a LASER cut, water jet cut ..., a stamping, a knife roll cut.

In the example shown, each first conductive element is located in a plane. In the example in Figure 1, the plane of each conductor is perpendicular to the plane of the substrate. The first conductive elements are arranged radially with respect to each other. The configuration and orientation of the connection bridges, which preferably extend in planes transverse to the substrate, makes it possible to substantially reduce the size of each bridge in the plane of the substrate.

Advantageously, the radially inner ends of the second conductive elements are on the same circle, and the radially inner ends of the second conductive elements are on the same circle. Thus the same first elements can be used for all the turns.

A toroidal inductive device is thus formed.

Each connection bridge forms part of a turn and each second conductive element forms another part of the turn, the proportions of the turn formed by the connection bridge and by the second conductive element are variable, preferably the proportions are 3/4 and 1/4 respectively.

In Figure 2B, we can see a variant of a first conductive element in which the connection ends comprise a tab 6. This variant is advantageous in the device of Figure 1 because the tab of the connecting end at the central part of the substrate is located on a larger diameter, which allows more space for connection between the connection end and the second conductor radially inside.

In Figure 2C we can see another variant of a first conductive element, in which each end has a tab 6 whose width represents only part of the width of the conductive path, for example half in the example shown. In this example, the tabs are located on the same side of the conductive path and the first conductive element is oriented so that the tabs are located radially on the outside. This variant is even more advantageous, because it provides a sufficient current flow section while ensuring a connection over a larger diameter. Alternatively, the legs are located in the center of the conductive path.

In the examples of FIGS. 2A to 2C, the electrical and mechanical connection between the connection bridges and the second conductive elements is carried out by inserting the tabs into the holes made in the substrate and by possible soldering.

As a variant, as shown in FIG. 2D, the connection bridge comprises two connection tabs 16 intended to come into plane support against the second connection elements and to be secured thereto, for example by soldering. For example solder paste 18 is interposed between each connection tab 16 and the second connection element E2.

It can be envisaged to overmold each first conductive element with an electrical insulating material except at the level of the electrical contacts.

In FIG. 9, one can see an example of an inductive device according to the invention comprising a large number of first conducting elements and therefore a large number of turns.

In FIG. 3, we can see another example of the first conductive element in the form of a printed circuit. It comprises an electrical insulating support 10 on and / or in which a conductive track 12 is formed forming the conductive path. Connection tabs 14 to the substrate are formed. As a variant, several tracks can be formed on one face of the printed circuit. In another variant, one or more electrical tracks can be produced on the two faces of the printed circuit, thus at least two portions of turns can be formed on the same printed circuit. We can also consider adding one or more electrical components to the printed circuit.

In this example, the connection bridges are contained in a plane.

According to the variant shown in Figure 6A, the connection bridges are contained in several planes. The Bl and B2 branches are contained in intersecting planes.

In FIG. 6B, we can see several bridges in FIG. 6A, seen from above, arranged one next to the other, illustrating the fact that they make it possible to produce an inductive device having a high density of turns.

As a variant, the connection bridges can be corrugated while looking in the direction of the Z axis.

In FIG. 7A, it is the connection portion 15 which is contained in a plane distinct from the branches. In FIG. 7B, we can see several bridges in FIG. 7A, seen from the side, arranged side by side, illustrating the fact that they make it possible to produce an inductive device having a high density of turns.

The examples of connection bridges in FIGS. 6A to 7B are arranged with respect to each other so as to fit together. Thus the shape in several planes nevertheless makes it possible to obtain a high density of turns.

The shape of the first conductive elements can have shapes other than a U shape, for example a V shape.

According to the invention, the plane or planes containing the connection portion 15 are not parallel to the substrate in order to reduce the footprint of the connection bridges

In an exemplary embodiment, the first conductive elements are mounted one by one on the substrate and electrically connected to the second conductive elements.

In another example of a preferred embodiment, all the connection bridges are arranged in a holding tool which simultaneously mounts all the connection bridges on the substrate.

The device of Figure 9 comprises an overmolding 20 is formed on the first conductive elements El forming a one-piece assembly, immobilizing the first conductive elements relative to each other before mounting on the substrate and facilitating the assembly of the first elements conductors on the substrate 2. The overmolded material is electrically insulating and provides protection. The overmolded material can advantageously participate at least in the mechanical joining of the first electrical conductive elements with the substrate 2. The overmolded material is for example a plastic material, for example TABS (acrylonitrile butadiene styrene), an epoxy resin, a silicone material

For example, the distance d between two radially inner ends of the first two conductive elements can be of the order of 1 mm ben the absence of overmolding (FIG. 1). In the case of an overmolding carried out on the first overmolded conducting elements, the distance d can be of the order of 0.3 mm (FIG. 9).

In FIG. 8, one can see an example of a substrate making it possible to produce two inductive devices, for example for example for producing a primary and a secondary of an electric transformer.

In this example, the first conductive elements and their relative arrangement are identical to those of the device in FIG. 1.

The substrate comprises groups of second electrical conductors. A first group of second electrical conductors participates in the electrical connection of first conductive elements El to each other to form the primary and a second group participates in the electrical connection of other first electrical conductive elements El to each other to form the secondary.

The references E2p designate the electrical conductors providing the connections between the first conductive elements El to form the primary and the references E2s designate the electrical conductors providing the connections between the first conductive elements El to form the secondary.

As can be seen in FIG. 8, advantageously the outer dialing ends of the second electrical connector elements E2p and E2s of the two groups are located on the same circle Cl and the radially inner ends of the second electrical connectors E2p and E2s of the two groups are located on the same circle C2. Thus by using the same connection bridges, two separate inductive devices can be produced.

As a variant, the two inductive devices are produced with connection bridges of different geometries, the connections to the second conductors being located on different circles.

It will be understood that more than two inductive devices can be produced simultaneously.

In this example, the second conductors E2p and the second conductors E2s are produced in separate planes.

In the examples described, the connection bridges are located on one side of the substrate.

[0123] In other examples, connection bridges are located on both sides of the substrate. It can then be envisaged to produce separate inductive devices on each of the faces and / or to produce one or more separate inductive devices on the two faces, each turn of a device being formed by a connection bridge on one side and a bridge. connection on the other side.

The inductive device or devices may or may not include cores made of magnetic material. Where separate inductive devices are made on both sides of the substrate, one may have a core and the other may not have one.

An example of a method for producing an inductive device in FIG. 1 according to the invention will now be described.

The first conductive elements are produced by cutting from a copper plate. The first conductive elements are for example those of FIG. 2A.

The substrate provided with second conductive elements is manufactured by the techniques of microelectronics, for example by etching of a printed circuit. Drill holes are made through the substrate at the inner and outer radial ends of the second conductive elements for the insertion of the electrical contacts of the first conductive elements.

The core is placed on the substrate.

The electrical contacts 6 of the first conductive elements El are inserted into the holes and overlap the core. For example, all the first elements are mounted in a tool to ensure simultaneous mounting of all the first conductive elements on the substrate. Soldering can be performed if required at each electrical contact in order to electrically connect each electrical contact to a second conductive element.

The inductive device is finished.

An over-molding on all of the first conductive elements can then be carried out.

The method according to the invention is particularly advantageous for manufacturing inductive devices with a closed contour, such as toric or E inductive devices. However, it will be understood that the present invention applies to inductive devices of any shape, for example to an inductive device in the form of a bar.

The invention is also very advantageous for producing several inductive devices simultaneously and having a reduced bulk.

The inductive device according to the invention can very advantageously allow the winding of the inductor of electric motors.

The invention also has the advantage of making it possible to integrate one or more inductive devices directly on a substrate comprising other electronic functions, for example the rectifying circuit of a transformer of an electronic power system. The diodes can be soldered to the substrate directly at the ends of the connection bridges providing the secondary of the transformer.

Claims (1)

Claims [Claim 1] Inductive assembly comprising at least n first conductive elements (E1) and a substrate (2) comprising at least n second conductive elements (E2), n being an integer greater than or equal to 1, each first conductive element (E1) extending to the at least partly in a plane different from the substrate (2), and comprising a first end (El.l) and a second end (El.2) connected by an electrical conductive path (CC), the conductive path (CC) comprising a first portion (Bl) provided with the first end (El.l), and a second portion (B2) provided with the second end (El.2), at least one of the first (Bl) and second (B2) portions being electrically connected to a second conductive element (E2) by the first or second end, and at least a third connection portion (15) between the first portion (Bl) and the second portion (B2), the conductive path (CC ) also comprising two faces (F) connected by edges (R), said faces having a very large area compared to that of the edges so that the conductive path (CC) has a small thickness (e), the faces (F) having a transverse dimension (L) relative to the direction of circulation of the electric current in said conductive path (CC), in which the first (Bl), second (B2) and third (15) portions are oriented so that the current lines (II, 12,13) flowing in the third portion (15) are located at different distances from the substrate in the transverse direction of the faces (F). [Claim 2] Inductive assembly according to claim 1, in which n is greater than or equal to 2 and in which a first portion (Bl) of an electrically conductive element is electrically connected to one of the second conductive elements (E2) by the first end (El. l), and a second portion (B2) of the electrically conductive element is electrically connected to the other of said second conductive elements (E2) by the second end (El.2). [Claim 3] Inductive assembly according to claim 1 or 2, wherein each first conductive element (El) is contained in one or more planes, each plane being orthogonal to the substrate. [Claim 4] Inductive assembly according to claim 1, 2 or 3, in which each first conductive element (El) is entirely contained in a plane distinct from the planes containing the other first conductive elements. [Claim 5] Inductive assembly according to one of claims 1 to 4, in which the n first conductive elements (El) and the n second conductive elements (E2) are electrically connected forming a single inductive device. [Claim 6] Inductive assembly according to one of claims 1 to 4, in which at least a first part of the first conductive elements and second conductive elements are electrically connected to each other and a second part of the first conductive elements and second conductive elements are electrically connected to each other and electrically isolated from the first part of the first conductive elements and second conductive elements, forming two inductive devices. [Claim 7] Inductive assembly according to one of claims 1 to 6, in which the first conductive elements have the shape of a U, the first (Bl) and second (B2) portions forming the branches of the U and the third portion (15) forms the bottom from the U. [Claim 8] Inductive assembly according to one of claims 1 to 7, in which the first (El.l) and second (El.2) ends comprise at least one connection tab 6 mechanical and / or electrical. [Claim 9] Inductive assembly according to claim 8, in which the substrate (2) has orifices (0) in which the connection tabs (6) are inserted. [Claim 10] Inductive assembly according to claim 9, in which each connection tab (6) is held in an orifice (0) by mechanical cooperation with the wall of the orifice (0) and / or by a solder. [Claim 11] Inductive assembly according to one of claims 1 to 10, comprising first conductive elements (El) on one side of the substrate and first conductive elements (El) on the other face of the substrate. [Claim 12] Inductive assembly according to one of the preceding claims, in which the n first conductive elements (El) and the n second conductive elements (E2) are distributed radially so as to form one or more inductive toric devices. [Claim 13] Inductive assembly according to one of the preceding claims, in which the second conductive elements are distributed in several substantially parallel planes of the substrate. [Claim 14] Inductive assembly according to one of the preceding claims, in which the first conductive elements (El) are cut from a plate of electrically conductive material. [Claim 15] Inductive assembly according to one of the preceding claims, in which each first conductive element (El) comprises a substrate (10) of electrical insulating material and a track (12) of electrical conductive material between the first and the second end and forming the conductive path. [Claim 16] Inductive assembly according to one of the preceding claims, in which the substrate is a printed circuit. [Claim 17] Inductive assembly according to one of the preceding claims, in which the first conductive elements are held integral with one another by an overmolded electrical insulating material. [Claim 18] An electrical transformer comprising at least one inductive assembly according to claim 6, wherein the first part of the first conductive elements and second conductive elements form a primary and the second part of the first conductive elements and second conductive elements form a secondary. [Claim 19] Method of manufacturing an inductive assembly according to one of claims 1 to 17, comprising: - the manufacture of n first conductive elements, - the manufacture of the substrate with the n second conductive elements, - the mounting of the n first conductive elements, comprising: - the mechanical fixing of the n first conductive elements to the substrate, - the electrical connection of each first conductive element to two second conductive elements. 1/6