FR2585504A1 - INDUCTIVE ELECTRONIC COMPONENT FOR FLAT DISPLAY AND METHOD FOR MANUFACTURING THE SAME - Google Patents

Abstract

THE INVENTION RELATES TO INDUCTIVE COMPONENTS THAT CAN BE TRANSFERRED TO FLAT AS WELL AS THEIR MANUFACTURING PROCESS. THE INDUCTIVE COMPONENT ACCORDING TO THE INVENTION IS OF THE TYPE A WIRE COIL AROUND A CORE 60 WHICH HAS A NOTCH 61 AT EACH OF ITS ENDS 68. THE ENDS 66 OF THE WIRE SPOOL 65 ARE FOLDED ON THE ENDS OF THE CORE, TRANSVERSALLY TO THE SLOTS AND THE EXTERNAL CONNECTIONS 63, 71 OF THE COMPONENT END IN THESE SLOTS. THE COIL CORE IS THEN COATED WITH RESIN 70 AND THE EXTERNAL CONNECTIONS ARE FOLDED ON THE RESIN BLOCK.

Description

INDUCTIVE ELECTRONIC COMPONENT FOR THE REPORT

  A FLAT AND METHOD OF MANUFACTURING THE SAME

  The present invention relates to an inductive component of the reportable type flat. This component may have an inductance

  predetermined, or possess an adjustable inductance or

  table. It can still be a transformer. The invention also relates to their manufacturing process. Reportable flat components are often referred to as Anglo-Saxon chips. They are used when it is necessary to obtain a high density of implantation of components on an electronic card. Most electrical functions are

  represented: resistors, capacitors whatever the dielectric

  trike, semiconductors. For reasons of their own, the

  inductors are poorly represented.

  Chip inductors are known that are wound in the manner of a conventional choke on a support or form of magnetic material or not, the winding consisting of an insulated wire, usually enamelled copper. Such chips cover a fairly wide inductance range (from a few nanohenries to a few millihenrys) and their quality coefficients are often high (Q 30). The admissible currents are well adapted to the most usual conditions

  of use in electronic circuits (from a few milli-

  ampere to one ampere). Unfortunately, they are often too big. The smallest known model has dimensions: 4.5 x 3.25 x 3.2 mm. In addition, they are not always usable with dip or wave soldering techniques. Their cost is generally high because their manufacture is difficult because of their small dimensions and the difficulty of connecting the

  ends of the winding at the terminations of connections. An inductive

  this type is described in the French patent application

the Applicant FR 2 548 821.

  Chip inductances obtained by screen printing or by another metallization technique of a drawing on an insulating substrate or on insulating substrates stacked with one another are also known.

  on the others and provided with a conductive passage ensuring continuity

  electrical nuance between each layer made. We can

  also deposit on these substrates a paste with magnetic properties.

  to improve the characteristics of the inductance obtained or to achieve shielding. Such chips are often smaller than those mentioned above. They include the standard format: 3.2 x 1.6 x 1.2 mm. They are generally inexpensive, well suited to the needs of "mainstream" equipment manufacturers and most often solderable by immersion dipping or wave. They are unfortunately limited in inductance values (from a few nanohenries to a few hundred microhenries). Their overvoltage coefficient is rather poor (Q 30) and they do not tolerate operating currents greater than 100 mA. Furthermore,

  production investment costs are high.

  It is therefore the field of wound coil inductances which seems the most interesting because of their good electrical performance. The invention will therefore relate to a micro-inductance chips wound on a support. It will have to solve the many problems which are attached to the realization of such products and which are well

known to those skilled in the art.

  It is necessary to reduce the losses caused in connections or metallizations of terminations and which limit the coefficient of overvoltage. The solutions proposed so far only increase the volume of the component and lead to very complicated embodiments. All these operations are difficult,

not very machinable and expensive.

  Another problem is the reduction of the parasitic capacitances whose effect is to lower the resonance frequency of the LC parallel circuit equivalent to the inductive component. If the interelectrode capacitance can be easily reduced, it is not the same

  the capacitance distributed between each turn of the coil.

  It is generally desired to obtain high inductance values despite the reduced dimensions of the components. The use of a magnetic core makes it possible to obtain a high inductance but significant losses can occur by hysteresis and by eddy currents. These losses reduce the coefficient of quality at high frequencies in a significant way unless using materials adapted to the high frequencies but whose permeability is unfortunately very low, which goes against the goal. The performances must be stable according to the temperature and the current of use. The characteristics of the magnetic material constituting the core are affected by the temperature and, by the play of the thermal expansion, the coils of the coils can play, thus modifying the values of the capacities

  distributed therefore the resonance frequency.

  The manufacturing processes of such components also have their constraints which result among other things, small dimensions of the winding support which makes it difficult to wind the wire. Another constraint is the welding of the ends of the winding to the output connections. This is made very difficult because of the small size of the winding core, the diameter of the wire and the presence of the enamel that covers it. The coating of the inductive component in a material resistant to immersion in a welding tank and protecting the enamelled wire also presents difficulties of production. In this connection, mention may be made of French patent application 2,509,529, which discloses an interesting method. However, this method includes a step during which the internal ends of the connections are twisted which is difficult to achieve given the small dimensions - desired. Moreover, the core used is poorly adapted to pressing techniques and its dimensions are subject to large

  tolerances due to withdrawal following cooking.

  To overcome these drawbacks, the invention proposes a composition

  Inductive health of original design and which can be obtained by a

  inexpensive and automatable manufacturing process.

  The subject of the invention is an inductive component that can be carried flat, of the wire type wound around a core, characterized in that the

  nucleus has at each of its ends a notch, the ends

  The external connections of the component terminating in these notches, each wire end being electrically connected to the corresponding connection, have protective means on which the connections are folded. ensuring

insulation of the wound core.

  The core on which the wire is wound has preferably a square or rectangular section. It may or may not be magnetic material.

  The component may also be provided with a magnetic bar

  tick designed to close the magnetic field with or without gap.

  The inductance of this component can be made variable or

  adjustable thanks to a movable magnetic bar.

  The invention also relates to a method of manufacturing an inductive component comprising the following steps: - winding the core by a wire whose ends protrude axially from the ends of the core, insertion of cores wound in housings made in a metal grid each housing being formed from an H-shaped cutout, the internal metal portions of said cut being folded under the insertion pressure until their edge is received in the notches of the core, - electrical connection between each end of the wound wire and the corresponding metal cut-out, setting up the protective means around each wound core, - cutting of the gate and folding of these cuts on faces of said

protective means.

  It is advantageous for the internal metal parts at each H-shaped cutout to have been previously arched for

  facilitate the insertion of wound cores in their homes.

  The invention will be better understood and other advantages apparent

  will be by means of the following description and figures

  in which: - Figure I shows a coil holder according to the invention; - Figures 2 and 3 show wound cores according to the invention; FIG. 4 represents a metal grid allowing the automated assembly of wound cores, FIGS. 5 and 6 are detailed views of the metal grid, FIGS. 7 and 8 are views illustrating steps of mounting the wound cores, FIG. 9 illustrates a method of welding the ends of the wound wire to the electrodes of the component, FIGS. 10 to 12 are equivalent electrical diagrams, FIG. 13 is an explanatory diagram, FIG. 14 illustrates the production line. according to a preferred embodiment of the invention, - Figure 15 is a sectional view of an inductive component at the end of manufacture,

  FIGS. 16 and 17 represent other possible embodiments.

  inductive components, - figures 18 and 19 show the way to identify the polarities of an inductive component, - figure 20 relates to a transformer according to the invention,

  - Figures 21 and 22 show variants of the invention.

  The inductive component according to the invention is made from the winding of a conductive wire on a support made of magnetic material

  or non-magnetic. Figure 1 shows such a support or core.

  It is advantageous to give it an H-shaped longitudinal section for reasons which will be explained below. In the case where the core is selected magnetic material, it may be ferrite or obtained from ferrite powder or iron powder, for example. If a non-magnetic material is chosen, it may be

  ceramic or a thermoplastic or thermosetting material.

  The simplified shape of the body I makes it possible to carry out the support by pressing or injection and as it is extrudable by spinning and cutting, which reduces the tooling costs. Side flanges

  2 are provided with notches 3, preferably of triangular shape.

  However, these cuts may have another shape: rectangular

  lair, semicircular or other. This shape can be obtained by extrusion or by machining. It is shallow, for example

  order of 0.15 mm so as not to alter the magnetic section.

  useful tick of the core when it is made of a suitable material. The external dimensions of the core (L, 1, h) are determined according to the desired dimensions for the coated component. As an indication, the dimensions of these cores can be: 2.8 × 0.8 × 0.8 mm × 2.8 × 1.6 × 1.3 mm or 4.1 × 2 × 1.6 mm

without this being restrictive.

  The notches 3, constituting one of the aspects of the invention,

  allow the fixing and centering of the core on the metal grid.

  which will be used to make the connections and the positioning

  correct of the wound assembly in the coating mold.

  Note that the coil portion of the core, located between the side flanges, has a geometry conducive to obtaining a high inductance due to a greater winding section with constant external dimensions than that of a pulley or dome. a dumbbell having recesses throughout its perimeter, as is the case for devices of the prior art. Moreover, the wire remains held in its housing by the recess d which can be very small (for example 0.2 mm), since the relatively large length e allows the winding of one or few layers, which reduces even the distributed capacities and allows the inductance to operate below the frequency

  resonance that can be high.

  FIG. 2 shows how the winding of the enamelled or insulated wire in any way is wrapped around the winding part which has just been described. This winding can be performed on a conventional machine driving the rotating core by gripping one or both lateral flanges between clips or other mechanical device, or better in the preferred embodiment by maintaining this fixed core while the wire is wound using a movable arm 4 comprising a wire guide 5 rotating about the xy axis and being able to guide the wire by linear displacement along the xy axis. This type of machine is well known to those skilled in the art. We can thus take advantage of the fact that the core is fixed to come to hold the ends of the wire 6 by two or four points of glue, wax or other adhesive 7 on the faces shown in Figure 2. It is sufficient for that the machine has a finger mobile that hangs the wire at the beginning and end of the winding and comes to flatten and immobilize it by gluing for example

  at the points 7 indicated. It should be noted that these glue points

  the ends of the winding wire into a perpendicular

  to the axis of the notch 3 or at least transversely to this axis. This position is one of the features of the invention because it will be seen later that it allows to have the wire correctly to facilitate its welding connections. It will be noted as shown in FIG. 3 that the glue points 7 can be reduced to two, leaving the ends of the threads 8 free, and that the

  Winding described is not restrictive.

  The windings thus wound and fixed are inserted into the slots 10 of a metal grid 11 shown in FIG. 4. This grid comprises in fact a series of identical successive cuts and can be prefabricated in the form of a roll of great length (several tens or hundreds of linear meters) the metal used being thin, flexible and easily weldable, such as tinned brass 1/10 mm thick for example. This grid has holes 12 on the margins so as to advance in automatic tools ensuring the insertion of cores wound in the slots 10, the welding of the winding son which will be described later, and the positioning of the assembly in cavities

of the coating mold.

2585504-

  The grid 1I1 also has other cutouts that serve

  It will be necessary to electrically connect the inductive component to its output electrodes. These cuts can be in different forms. In Figure 4, there is associated with each light 10, four cutouts 13 L-shaped frame that surround this light. This arrangement is advantageous because it delimits the outline of the

  future electrodes of the component while maintaining sufficient rigidity

  health for the operation of the grid.

  Figures 5 and 6 show particular details of the light 10 practiced in the grid 11 and which characterize several interesting features of the invention. The camber 0 of the portion 14 of the central cutout will allow the clipping of the core in its notches 3. Two rectangular cutouts 15, diametrically opposed to the light 10, are also provided. Their role will be specified later. The different cuts made in the grid 11 can be obtained by stamping. Folding parts 14

  can also be obtained by stamping.

  Figure 7 illustrates the operation of inserting a wound core in its housing. The wound core is pushed in the direction indicated by the arrow in the hollow formed by the folded portions 14. The insertion of a wound core such as that of FIG. 3 has been chosen in a nonlimiting manner. parts 14 (clearly visible in Figure 5) guides the free ends of the son 8, during this insertion movement, along the outer walls of the side flanges 2 of the core. When the core is locked in its final position by clipping of the grid 1 in the notch 3, the wire ends are automatically positioned under the grid and centered in the hollow of V above indicated. It will be noted that during this

  movement the insulated wire, for example by an enamel, is rubbed

  on the V-shaped cutting edge of the portion 14 which tends to strip the insulation and thus initiate a beginning of electrical continuity between these wire ends and the lead frame. This feature is exploited to facilitate and initiate the welding operation which will be described later. We

2585504 '

  note further, Figures 5 and 6, that another opening 15 is made in the grid, in the arched portion located below the V-shaped footprint. This cut reduces the contact area that can be bathed by the flow of induction, although this contact is removed from the core by an air gap f as shown in Figure 7. These two features significantly reduce the eddy current losses induced in the frames and allow

  to ensure a significant overvoltage coefficient, even at frequencies

  high frequencies. This same opening 15 also reduces the interelectrode capacitance by minimizing the opposite surfaces, and

  thus makes it possible to obtain a high resonance frequency.

  To facilitate and mechanize the insertion operation of the wound core in the grid, the latter is held in a tool

  shown in FIG. 8. This tool comprises a platform

  form 20 provided with lugs 21 for fixing and centering the grid 11, whose lights are facing a groove 22 formed in the platform. This groove and the positioning of the grid in these lugs ensures a centered clipping of the wound core so that the subsequent molding operation

  operated under good conditions, ensuring an inclusive inclusion

  made of the whole grid-cores in the coating mass. This insertion operation can be mechanized by the use of a

  tooling "to be followed" equipped with a distributor of wound cores

  both an insertion head placed facing the groove under which the grid 11 passes. The lugs 21 making it possible to fix the grid on the platform 20 can be engaged in the other cutouts of the

  grid, for example the holes 12 or the cutouts 13.

  A coil such as that shown in Figure 2 can of course be mounted in the slot 10 as previously indicated. It does not benefit from pre-stripping due to friction with the grid

  since the ends of the wire are already folded.

  On the same insertion tool, or on separate equipment, the wound cores thus inserted are presented between the poles of an electromagnet 23 shown in FIG.

2585504 '

  alternating current 24, at high frequency (for example 100 kHz), is connected to the winding 25 of the electromagnet and induces in the chip inductance 26 a voltage which can reach a value sufficient to produce an arc between the ends wire 27 and the parts of the grid 11 in contact with this wire or close very close. We have seen above that the ends of the wound wire could be predecaped by the insertion operation in the grid which

  facilitates the welding of the wire on the grid.

  Figure 10 shows the electrical equivalent diagram to this device. It shows the generator 24, the electromagnet 23, the inductor 26, the gate 1 and the gaps 30 constituted by the space separating the coil winding wire and its gate. This arc establishes a weld between the ends of the winding wire and the V contacts above-reported. Note that one of the arcs is necessarily hotter than the other because the burst distances gl and g2 are not necessarily equal, the weld can be established only one side at a time, but as soon as the contact is made on one side, all the induced voltage is found on the other spark gap which ensures the welding on the other side. As soon as the contacts are made, the equivalent diagram takes the appearance of FIG. 11, where the imperfect welds are represented by the resistors 31. The secondary of the equivalent transformer is then traversed by a quasi-short-circuit current, causing the heating of the resistors 31, as in the well-known method of spot welding. The welding of the two ends of winding is then ensured perfectly. The equivalent diagram is then represented in FIG.

  intense current I then travels the secondary, that is to say, the bobbin

  swimming inductance chips. We can use this current to

  warm up the wire if it is chosen covered with a thermal enameling

  member. This completes the solidarity of the turns between them, which has the result of ensuring a greater strength of the winding, to prevent it from being unwound during subsequent manipulations and especially to stabilize its electrical characteristics, the distributed capacity including which will remain stable according to the

2585504 '

  i11 temperature which will ensure a very great independence of the

  resonance frequency as a function of temperature.

  Furthermore, the high-frequency generator 24 shown in FIGS. 10, 11 and 12 is programmed as follows, illustrated in FIG. 13, which represents the amplitude and the voltage v developed at the terminals of the winding of the chips, and the current i which flows therethrough. time t. There are four periods: t to t, t1 t to t2, t2 to t3, t3 to t4. During the interval to t1 the developed voltage is maximum v = E (100 volts for example) and as the arc has not yet burst the current i is zero. From t1 to t2 the arc springs, the tension v falls and the current i increases abruptly. From t2 to t3 the point welding with low voltage and high current i takes place, which makes it possible to obtain moreover the thermoadherence of the wire. From t3 to t4 the voltage v and hence the current i are progressively reduced so as to obtain the demagnetisation of the core which could possess

  a residual magnetization of origin, due to the preceding manipulations

  dentes in the various tools or caused by the operation of

solder described above.

  Of course other more known welding processes can be used: soldering tin / lead soldering iron or appropriate tools, solder paste, hot gas jet welding, induction welding, laser welding, cold welding with conductive glue ... It is also possible to associate with the preferred system described the conventional methods

  cited, such as the welding in the gap of an electro-

  magnet after having previously coated the contacts with solder paste. Under this welding operation, there is a metal grid in which are inserted and centered cores

  coils whose turns can be agglomerated by thermo-

  adhesion and whose ends are welded in contact with the grid. The last phases of the manufacturing process are better known. The grid is placed in a coating mold which may be of the transfer type, liquid injection, or casting of epoxy resin for example. After demolding the grid is presented under

2585504 "

  a trimming / bending tool that cuts the free ends of the grid and camber them around the resulting shape to make the output connections. The pieces can then be

  checked, marked and packaged in super 8 tape for example.

  Figure 14 shows the manufacturing line according to the preferred embodiment of the invention. In this figure, the reference 40 represents the operation of winding and fixing by glue point 41 of the ends of son. The wound cores obtained are poured into a vibrating bowl 42, for example of the electromagnetic type, or any

  another distribution system which supplies a store 43 placed

  above the insertion head 44. The bottom of Figure 14 represents a

  "online" equipment which could also be a "carousel tour-

  In this equipment, the grid 45 is fed from a roller 46 and is driven by the rotation of the wheel 47 which recovers the unused portions of the grid.In its linear movement, the grid is in front of the wheel. assembly / insertion tooling 48 provided with positioning pins 49 and a calibrated groove 50. The wound and inserted cores are then moved in the air gap of

  the welding electromagnet 51 powered by the generator

  52. The windings thus fixed and welded are embedded in the two-part mold 53 which has cavities 54 in which the resin is injected after the mold has been closed by pressing 55 of the two movable parts 53. The overmolded elements 56 pass by then in front of a clipping / shaping tool

  a fixed part 57 and a mobile cutting / bending tool 58.

  The completed component is shown in Figure 15 where it is recognized

  is born all the parts described previously. In this figure appears the core 60, provided with a groove 61 in which are clipped the fingers V62, the grid provided with openings 64 for

  reduce the induced eddy currents and the interelectricity capac-

  trodes. The insulated wire 65 is wound on the core and its ends 66 fixed by glue points 67 are folded along the lateral flanges 68 transversely to the groove 61. The weld 69 is formed in the hollow of the V-shape. A resin coating 70 protects all the parts included while the free ends of the grid as they appear after cutting are folded on the lateral outer faces 72 so as to achieve

  the connections 63 and 71 of the inductive component.

  Different presentations of the output electrodes are of course possible. FIG. 16 represents the completed chip in the form of a resin parallelepiped 75 including the wound core and provided with lateral connections 76, for example made of tinned brass. The electrodes 76 have the advantage of coming out of the resin block by one of the large faces of the parallelepiped before being folded, which further facilitates soldering by direct transfer. A more interesting variant of the finished chip is shown in FIG. 17. The connections 77 are folded over several or all the faces of the resin block 78 thus allowing all the types of transfer, flat and field. The dimensions of the components obtained are, for example: 3.2 × 1.6 × 1.2 mm or 4.5 × 3.2 × 2 mm or preferentially

3.2 x 2.5 x 2 mm.

  Further improvements can be made to the

  described. It may be useful to be able to identify from the outside the input and output connections of the winding so as to know the north and south poles of the inductance produced, which can avoid or use phenomena of magnetic coupling between two or more chips reported on a card.

  For this purpose, the core 80 shown in FIG. 18 comprises a chamfer 81 on one of the side flanges so that it can be presented to the winding only in one position so that the winding is always performed in the same direction. direction of rotation poles N and S are perfectly identified. After

  winding, these cores are oriented by means of the preceding vibrating bowl

  described which recognizes the chamfer in such a way that they are always inserted with the same orientation in the connecting grid, which is voluntarily asymmetrical. One can for this purpose provide an asymmetrical cut in the grid such that after its final cut, it leaves a mark 82 on a single connection 83. The other connection 84 does not bear this mark, it is easy to identify the meaning of winding. It is within the scope of the invention to identify the inductive component by other signs on one of the

connections or both.

  The description has so far focused on an inductor

  bipole. However, it is not limited to the manufacture of this single component.

  FIG. 20 represents a transformer whose coils

  Primary 85 and secondary 86 are wound around a core 87 provided with two lateral cheeks 88 in which are cut notches 89 and a side wall 90 separating and insulating the two windings whose ends 91 are also fixed by means of glue points 92. This wound core can be inserted into a grid having two pairs of contacts instead of one. The methods of winding, bonding the ends of wire, insertion,

  welding, coating and trimming / bending described above.

  are applicable to this transformer. It is also possible to use closed or low-gap core shapes as shown in FIG. 21 so as to increase the values of possible inductances or to obtain a shielding effect. The core 100

  has a central part on which is wound the enamelled wire.

  The ends of this wire are fixed by glue points 101 on opposite edges of a face of the core. The core further comprises two flanges 102 flanking the central portion on which there are provided notches 103 which will allow the fixing and centering of the core on the metal grid described above. The core can be closed by the magnetic bar 104 with or without gap. The fixing of the bar on the core can be done by means

mechanical or by gluing.

  It is also within the scope of the invention to produce adjustable inductors. In this case it is preferable to install this inductor in a housing rather than embedding it in a coating resin. Figure 22 shows such an inductance. The wound core 110 is of the type already described. The contacts 111 are, as before, from a metal grid. The step of coating the inductive components has been replaced by a step of placing these components in housings 112 made of plastic or metal. The implementation of the components in the housings can be done in the following manner. The portion 113 of the housing, equipped with the worm 114 and the magnetic bar 115, is disposed in the cavity bearing the reference 54 in FIG. 14. By pressing according to the arrows 55, it is placed, slightly in force, the bottom 116. The following operations are known: we proceed to the cutting

  contacts 111 and at their simultaneous folding to obtain the

  22. By acting on the wheel 116 secured to the screw 114, the moving bar 115 is moved so as to close more or less the magnetic circuit formed by the core 110 bar 115. If the casing 112 is metallic,

it can act as a shield.

Claims (21)

  1. inductive component reportable flat, wire type wound around a core, characterized in that the core (60) has at each of its ends (68) a notch (61), the ends (66) of the wire coil (65) being folded over the ends of the core and transversely to the notches, the external connections (63,171) of the component terminating in these notches, each wire end being electrically connected to the corresponding connection, protective means (70), on which are folded the connections,   ensuring the insulation of the wound core.   2. Inductive component according to claim 1, characterized in that the part of the core on which is wound said wire (65) has a rectangular section.   3. Inductive component according to one of claims 1 or 2,   characterized in that the core (60) is of magnetic material.   4. Inductive component according to any one of the   cations 1 to 3, characterized in that the ends of the core (68) form flanges of greater thickness than the portion of the core for winding.   5. Inductive component according to any of the claims   I to 4, characterized in that the wire ends (8) are attached to the core ends (2) by at least two points of glue (7).   6. Inductive component according to claim 5, characterized in that each end of wire (6) is fixed on the core ends (2) by two points of glue (7) located on either side of the corresponding notch (3).   An inductive component according to any of the claims   cations, characterized in that said notch (61) is of triangular shape.   8. An inductive component according to any of the claims   cations 1 to 7, characterized in that the parts of the connections   (63, 71) leading into the notches (61) are   to form fingers that engage in these cuts, the   wire ends (66) passing between these fingers.   An inductive component according to any of the claims   I to 8, characterized in that the wire ends (66) are electrically connected to the outer connections (63, 71) by soldering (69).   An inductive component according to any of the claims   I to 9, characterized in that the core (90) supports two   coils (85, 86) to constitute a transformer.   An inductive component according to any of the claims   cations 3 to 10, characterized in that it further comprises a magnetic bar (104) for closing the magnetic field with or without gap.   12. An inductive component according to any of the claims   cations 1 to 1, characterized in that said protective means are   constituted by a resin coating (70).   13. An inductive component according to any of the claims   3 to 10, characterized in that it further comprises a movable magnetic bar (115) making it possible to vary the value of the inductance of the component.   14. Inductive component according to claim 13, characterized in that the protective means consist of a housing (112).   15. An inductive component according to any of the claims   1 to 14, characterized in that the external connections (63, 71) are provided with openings (64) for restricting the cross section.   said connections near the core (60).   16. A method of manufacturing inductive components according to claim 1, characterized in that it comprises the following steps: - winding (40) of the core by a wire whose ends protrude axially from the ends of the core, - insertion of cores wound in housings formed in a metal grid (45), each housing being constituted from a H-shaped cutout, the metal parts internal to this cut being folded under the insertion pressure until their edge comes to housed in the kerf cuts, - electrical connection between each end of the wound wire and the corresponding metal cutout, - establishment of the protective means around each wound core, - cutting of the grid and folding of these blanks on faces of said protective means.   17. The method of claim 16, characterized in that the internal metal parts (14) at each H-shaped cut have been previously arched to facilitate the insertion of the cores wound in their homes.   18. Method according to one of claims 16 or 17, characterized   in that the internal metal parts at each H-shaped cutout have a V-shaped opening for guiding the ends of the wound wire during the insertion operation and possibly its pre-aging.   19. Process according to any one of Claims 16 to 18,   characterized in that said electrical connections are made by a solder produced by induction of a voltage from a   electromagnet (51) and by electric arc.   20. Process according to claim 19, characterized in that the   induced voltage is controlled to obtain the demagnet- nuclei.   21. Process according to any one of claims 16 to 20,   characterized in that the protective means are set up by pressing (55) in a mold (53).