EP0473875A1 - Method for producing a HF-magnetic coil device in chip-construction - Google Patents

Abstract

An RF magnetic coil device, for example a ring-core transmitter, in miniature or chip construction, having a base body (1) of plastic which has recesses for magnetic cores (2) and contains electrical conductor tracks (5) on its upper side (10) and its lower side (11) and, in its interior, is provided with through-plated holes (16) to which the conductor tracks (5) are connected such that individual turns are formed around the magnetic core which produce windings of coils (6, 7). In addition, methods are specified which allow these devices to be produced in large quantities. <IMAGE>

Description

The invention relates to RF magnet coil arrangements in chip design, comprising an annular magnetic core embedded in plastic material and at least one winding made of at least one turn and guided through the magnetic core, the turns consisting of conductor track parts running parallel to the end face of the magnetic core and parallel to Axle of the magnetic core extending and inserted in the plastic embedded conductor track parts are assembled.

The invention further relates to methods for producing such RF magnet coil arrangements.

With the increasing miniaturization of electrical circuits, which has led in particular to surface-mounted circuits (SMD) with components in the so-called "chip" design, there is a need to also use HF magnet coil arrangements, such as toroidal transformers, with magnet cores Provided chokes, transformers, coils and the like, with very small dimensions in chip design. Annular magnetic cores, which have an outer diameter of less than 6.3 mm and accordingly an inner diameter of the bore of less than 2 mm, can practically no longer be wound with automatic winding machines. With an inner diameter of the bore of 2 mm, winding by hand is still possible, but this is not possible for large quantities due to price reasons and, moreover, does not lead to the required tight tolerances of the electrical values. The winding shapes that cannot be observed exactly do not only cause deviations in the inductance values, but also lead to very large variations in the capacity values.

US Pat. No. 4,536,733 describes an RF transmitter with a toroidal core made of ferrite material for energy supply, one winding of which consists of wire wound on the toroidal core and the second winding of which consists of individual, correspondingly shaped sheet metal parts which, together with printed ones Conductor tracks on a circuit board that result in turns of the winding. This embodiment is not applicable to the present invention.

JP-AS 1-278707, published in Patents Abstracts of Japan, E-882, Jan. 31, 1990, Vol.14 / No.55, describes an induction coil in chip design and a method for its production. At least two parallel rows of holes are created in a flat body made of magnetic material. Between these rows of holes, conductor tracks are formed on the upper flat side of the body parallel to one another and perpendicular to the edge sides and on the lower flat side of the body also parallel to one another, but at an acute angle to the edge sides, that is to say arranged obliquely over this flat side, in such a way that they run helically around the body and adjoin two holes on the lower flat side. The holes are metallized on their inner surfaces, so that a coil-shaped circuit results. This structure and this manufacturing method differ fundamentally from those of the present invention because the conductor tracks are applied directly to the body made of magnetic material and the body is not annular.

US Pat. No. 3,477,051 describes a magnetic coil arrangement in chip design which contains an annular magnetic core embedded in plastic material and at least one winding made of at least one turn and guided through the magnetic core, the turns consisting of conductor track parts and which run parallel to the end face of the magnetic core are composed of conductor track parts running parallel to the axis of the magnetic core and inserted in the embedding plastic. The potting plastic is injection molded around the entire toroid, i.e. both on the two end faces and on the outer surface and the inner surface of the interior of the toroid, produced in one operation. In this operation, channels are simultaneously stamped into the embedding plastic in such a way that these channels run helically around the ring core in accordance with the desired coil. The channels are later filled with metal or their surfaces are metallized, so that a magnetic component results, which has at least one winding consisting of turns. This component is then placed on a carrier body or in recesses of a carrier body which has the shape of the chip with corresponding connection and contacting surfaces with which the ends of the at least one winding are electrically connected.

US Pat. No. 3,486,149 describes an improved production of the magnetic coil arrangement just illustrated. In the process of reshaping the ring-shaped magnetic core, not only is this core encased in a plastic body with recesses for the coil turns, but at the same time a housing is also produced, which is also provided with corresponding recesses for conductor tracks to connection areas and with plated-through holes in this process. The housing is preferably rectangular and flat and has pins on one of its narrow side surfaces for use in holes in printed circuits. This does not result in a chip-type component. In contrast to the present invention, the magnetic coil arrangements described in the two US patents have, as conductor tracks, at least on the two end faces and in the interior of the core metallized grooves, which already during the production of the plastic covering in one forming operation by means of a suitably designed, complicated process Injection molding tool are generated, each magnetic core must be guided past this tool, or a large number of such tools must be provided if you want to ensure rational production. It is also not provided to fill the interior of the core with plastic during the sheathing, so that a further operation is necessary if, for. B. for reasons of insulation of the interior or all conductor tracks should be covered with plastic. The RF magnet coil arrangement according to the present invention differs from the known embodiments in particular in that the conductor tracks on the end faces are not arranged in channels, but on the faces and in that the electrical connections of the conductor tracks of the two end faces to one another outside and inside the core are present in holes. The resulting advantages of design and manufacture are explained in the context of the description of the invention.

The invention is based on the object of specifying an HF magnet coil arrangement of the type described in the introduction, in particular a toroidal core transformer arrangement, which can be produced completely or largely by machine and in very large numbers, the electrical of which Properties in the finished state, both as a function of frequency and for the given number of pieces, are very constant and can be easily installed in SMD circuits.

To achieve this object, the HF magnet coil arrangement is characterized according to the invention by the features of claim 1.

A preferred embodiment is characterized according to the invention by the features of the independent claim 2.

According to the invention, further embodiments are characterized by the features of the subclaims to the subject claims.

The methods for producing these arrangements are characterized according to the invention by the features of the independent claims 11 and 16.

Particular embodiments of these methods are characterized according to the invention by the features of the subclaims to these method claims.

In the context of this invention, the term “ring-shaped magnetic core” encompasses all magnetic cores which have at least one through opening surrounded by magnetic material; the magnetic cores can thus also be rectangular, square or oval and they can also have more than one opening, e.g. Double-hole cores. In these cases, the recess in the base body must of course be adapted to the cross-sectional shape of the magnetic core.

In the context of this invention, the term “RF magnet coil arrangement” also includes that other electrical ones Components, for example capacitors or resistors, which are integrated on or on the surfaces of the base body or in its interior, can be present. For the sake of simplicity, however, the invention is only described on the basis of individual arrangements with magnetic cores which have a circular cross section.

The invention is explained in more detail below.

The basic idea of the invention is to assemble the individual windings of the at least one winding both by surface-mounted conductor track parts and by through-holes located in bores, in order to ensure complete or largely complete mechanical, but also inexpensive series production with a consistently high quality to achieve the electrical properties. An essential aspect of the invention is seen in the fact that a base body is used in which the toroidal core is inserted and that the portions of the individual turns running parallel to the axis of the toroidal core are accommodated in bores of this base body. Depending on the material used and its thickness, bores with diameters up to 0.1 mm can still be mastered with metal drills. Laser drilling is recommended for even smaller bore diameters. These holes are then plated through, for which different methods are available depending on the material and dimensions. With larger diameters in the region of 0.3 mm, one can either press electrically conductive paste into these holes or press in liquid solder. An electroplating process is of particular importance here. The surface electroplating of plastic bodies with electrically conductive coatings is well known. With very small bore diameters, however, there is a risk that that the electroplating liquid no longer penetrates into the hole by itself. In this case, it is possible to create a vacuum above the electroplating bath that receives the base body, at least for a short time or also pulsatingly, whereby the electroplating liquid is sucked into the capillary-shaped bore. By using ultrasound, high penetration depths can be achieved even in narrow bores.

The base body used, which receives the magnetic core, is either laminated on its one side, called the base side, either before it is plated through the bores with the corresponding sections of the turns running perpendicular to the bores, or this lamination is carried out only subsequently. This lamination can be done either by providing the entire surface with an electrically conductive coating and etching off the parts that are not required, or by printing or vapor-coating the corresponding conductor tracks separately. The then still missing parts for completing the coils are achieved by a cover part which is applied to the base body on the side opposite the base part and which contains conductor tracks laminated on similarly to the base part. Depending on the technology used, this cover part can be applied before or after the drilling process.

The through-contacting of conductor tracks is known. If this technology is used, the lid can be retrofitted. The other possibility is to apply the cover before drilling and at the same time to drill through with the base body and to make contact with one of the methods specified.

Since all of these process steps can be carried out mechanically, a large number of such coils or toroidal core transformers can be produced simultaneously in a grid of, for example, 100 x 100 elements, and the finished components are subsequently, as is known from wafers, by sawing or another separation process isolated.

Instead of providing a base body in which the metallic connections parallel to the axis of the magnetic core are subsequently realized via bores, one can also proceed in such a way that these conductor webs are formed by layer-by-layer application of electrically conductive material. In this case, a base plate is used, on which electrically conductive material, for example silver, is applied, for example vapor-deposited or printed, at locations where these conductor tracks are to be produced. This method can be used to produce metallic columns of the desired order of several millimeters in length and diameters of approximately 0.1 mm, it being possible to carry out the application process in several stages in order to harden or mechanically harden the material already applied stabilize. With this method, it is recommended to arrange the magnetic cores on this base plate before applying the columnar conductor tracks and to fix them firmly with this plate, so that these columnar conductor webs can then be brought in close proximity to the system against the magnetic cores. The space between the surface and the upper edge of the magnetic cores, which has not yet been filled, is then filled by electrically insulating material, for example plastic, with an immersion bath or a spraying or printing process being suitable for this purpose.

A similar method of forming columnar traces can be achieved using whisker technology. It is a process that has been known for years, in which, by electrolytic deposition and in particular by condensation from the gas phase, metals can also be formed by germ growth, usually in a hydrocarbon atmosphere, material rods with diameters up to 1 µm and lengths up to several millimeters.

• a) eine vorgefertigte Platte aus Gießharz wird mit einer Matrix einer Vielzahl von die Ausnehmung ergebenden, durchgehenden Öffnungen und wenigstens zwei Referenzöffnungen versehen und auf eine ebene, geheizte Unterlage gelegt, wonach in jede Ausnehmung Gießharz in einer Menge gefüllt wird, die das Volumen des später einzusetzenden Magnetkernes berücksichtigt,
• b) in die Öffnungen werden elektrisch und auf Maßhaltigkeit geprüfte Ringmagnetkerne aus Ferritmaterial eingesetzt, gegebenenfalls noch vorhandene Leerräume insbesondere im Innenraum der Magnetkerne werden mit Gießharz gefüllt,
• c) Trocknen der so vorbereiteten Platte bei 60^oC und danach Aushärten bei 120^oC,
• d) erforderlichenfalls werden die großen Flächen der Platten planparallel geschliffen,
• e) Aufbringen von je einer gereinigten Verbundfolie (Dicke 25 m) aus einer Folie aus Polyimid, das hochwarmfest ist und keine Schmelztemperatur besitzt (Kapton-Folie), und Kupfer (Dicke 17µm) auf die planparallelen Flächen der Platte,
• f) erneutes Trocknen der so vorbereiteten Platte, eingespannt zwischen zwei Heizplatten, bei 60^oC und danach Aushärten bei 120^oC,
• g) definiertes Anordnen der Platte auf einer Vorrichtung unter Ausnutzung der Referenzöffnungen als Zentrierhilfe und rechnergesteuertes Erzeugen der Bohrungen für die Durchkontaktierungen entsprechend einem vorgegebenen, die gewünschten Windungszahlen berücksichtigenden Muster,
• h) Erzeugen der Durchkontaktierungen in den Bohrungen durch galvanisches Abscheiden von Metall (Kupfer) an den Innenwänden der Bohrungen nach an sich bekannten Verfahren,
• i) Erzeugen
  • der Leiterbahnen, die die Metallisierungen in den Bohrungen entsprechend der für die Windungen der Wicklungen erforderlichen Führung verbinden,
  • der Kontaktflächen für die Verbindung der Wicklungen mit der gedruckten SMD-Schaltung,
  • und der Leiterbahnen, die die Enden der jeweiligen Wicklungen mit den Kontaktflächen verbinden,
  entsprechend dem gleichzeitig für den Verfahrensschritt g) gültigen vorgegebenen Muster durch Ätzen der Kupferfolie nach für die Herstellung gedruckter Schaltungen bekannten Verfahren,
• j) automatische elektrische Prüfung der fertigen Übertrager und davor oder danach Aufteilen der Platte in die einzelnen Übertrager insbesondere durch Sägen längs vorgegebener Trennlinien,
  Eine Abänderung dieses Verfahrens sieht vor, daß anstelle einer Platte aus Gießharz eine Platte aus thermoplastischem Kunststoff eingesetzt wird und die Räume in den Öffnungen zwischen den Magnetkernen und der Platte mit härtbarem Gießharz ausgefüllt werden.

A preferred further process consists of the following process steps:

• a) a prefabricated plate made of casting resin is provided with a matrix of a plurality of through openings and at least two reference openings resulting in the recess and placed on a flat, heated surface, after which casting resin is filled into each recess in an amount which corresponds to the volume of the later the magnetic core to be used,
• b) electrical and magnetically tested ring magnetic cores made of ferrite material are inserted into the openings, empty spaces which may still be present, in particular in the interior of the magnetic cores, are filled with casting resin,
• c) drying the plate prepared in this way at 60 ^° C. and then curing at 120 ^° C.,
• d) if necessary, the large areas of the plates are ground plane-parallel,
• e) Application of a cleaned composite film (thickness 25 m) made of a film made of polyimide, which is highly heat-resistant and has no melting temperature (Kapton film), and copper (Thickness 17 µm) on the plane-parallel surfaces of the plate,
• f) drying the prepared plate again, clamped between two heating plates, at 60 ^o C and then curing at 120 ^o C,
• g) a defined arrangement of the plate on a device using the reference openings as a centering aid and computer-controlled creation of the holes for the through-plating in accordance with a predetermined pattern that takes into account the desired number of turns,
• h) producing the plated-through holes in the bores by galvanic deposition of metal (copper) on the inner walls of the bores by methods known per se,
• i) Generate
  • the conductor tracks that connect the metallizations in the holes according to the guidance required for the windings of the windings,
  • the contact surfaces for connecting the windings to the printed SMD circuit,
  • and the conductor tracks that connect the ends of the respective windings to the contact areas,
  in accordance with the predetermined pattern that is also valid for process step g), by etching the copper foil according to methods known for the production of printed circuits
• j) automatic electrical testing of the finished transducers and before or after dividing the plate into the individual ones Transformer especially by sawing along predetermined dividing lines,
  A modification of this method provides that instead of a plate made of casting resin, a plate made of thermoplastic material is used and the spaces in the openings between the magnetic cores and the plate are filled with hardenable casting resin.

Based on the embodiments shown in the figures, the invention is explained together with embodiments.

• Fig. 1 einen Schnitt durch einen Ringkernübertrager mit Deckelund Bodenteil,
• Fig. 2 einen aufgeschnittenen Ringkernübertrager nach Fig. 1,
• Fig. 3 eine gegenüber den Fig. 1 und 2 verbesserte Ausführungsform eines Ringkernübertragers mit durchgehender Ausnehmung, perspektivisch,
• Fig. 4 einen Schnitt durch den Ringkernübertrager nach Fig. 3.

Show it:

• 1 shows a section through a toroidal core transformer with cover and base part,
• 2 shows a cut toroidal transformer according to FIG. 1,
• 3 is an improved embodiment of a toroidal core transformer with a continuous recess compared to FIGS. 1 and 2, in perspective,
• 4 shows a section through the toroidal core transformer according to FIG. 3.

1 consists of a base body 1, an annular magnetic core 2 inserted therein and a cover 3. The base body 1 is designed, for example, as a thermoplastic body and has a recess the size of the magnetic core 2. The magnetic core 2 is inserted into this recess. The magnetic core 2 has an outer diameter of approximately 4 mm and an inner diameter of approx. 1.5 mm. The base body 1 consists, for example, of thermoplastic material, in which the recess for the magnetic core is already provided during the production, or of a material in which this recess is made subsequently, for example by drilling.

The magnetic core 2 inserted into the base body 1 is flush with the surface of the base body 1. The height of the base body 1 is approximately 0.5 mm greater than the height of the magnetic core, so that the base body 1 has a closed, non-perforated bottom surface 4. The cover 3 has a layer thickness of approximately 1 mm. The outer surface of the cover 3 and the bottom surface of the base body 1 have vapor-deposited or printed electrical conductor tracks 5, the ends of which each connect a point above or below the core bore of the magnetic core 2 with a point outside the magnetic core 2.

2 very clearly shows the conductor guidance in a toroidal core transformer with two coils 6 and 7. The respectively horizontal conductor track parts of the turns are formed by the already mentioned conductor tracks 5 on the cover 3 or the bottom surface 4 of the base body 1. The respectively vertical sections 8 of the turns of the coils 6 and 7 are realized by bores which run through the base body 1 in the axial direction of the magnetic core 2. In the exemplary embodiment shown, these bores have a bore diameter of 0.3 mm. They are filled with electrically conductive material and each connect an electrical conductor track on the bottom surface 4 with a conductor track on the cover 3.

In the following a manufacturing method for a toroidal transformer is described, in which the recess in Basic body is not continuous, according to FIGS. 1 and 2.

In a matrix plate made of thermoplastic material of 16 cm x 16 cm, 20 x 20 = 400 recesses for 400 ring cores are provided at intervals of 8 mm. This matrix plate is equipped with 400 magnetic cores 2 of the dimensions given above. The matrix plate has a thin copper layer on its bottom surface, as is known from printed circuits; if necessary, it can also be underlaid with a thin polylimide film (Kapton film). The cover part 3 is then glued or welded onto the assembled matrix plate. The cover part 3 also has a continuous conductor layer on its outside. Then the individual holes are drilled through the cover part 3 and the matrix plate in an automatic process, which holes are to form the already mentioned vertical sections 8 of the coils 6 and 7. A laser drilling method or a mechanical drilling method is suitable for this method, for example. With mechanical drilling, bore diameters of up to 0.1 mm can be handled, while even smaller laser beams can be reproduced.

The bores are then completely or partially filled with electrically conductive material in such a way that there is a plated-through hole between the electrical conductor tracks of the base surface and the cover 3. Either electrically conductive paste can be used for this purpose, which is injected under pressure in the case of very small bore diameters, or a process of galvanic metallization of plastic surfaces is used. In the case of very small bore diameters, it is advisable to expel the air contained in the bore by using a vacuum. Since the bottom surface 4 of the matrix plate is completely closed except for the holes, this surface can also be used pressurize it and press the plating liquid through the holes from this side or process it on this side with negative pressure in order to suck it through from the other side until the holes are completely or partially closed.

Suitable methods are described, for example, in the magazine "productronic 1/2 - 1988, pages 80-82" in connection with the through-contacting of printed circuit boards. In particular, the pinch rolling method mentioned there for forced flooding of the holes appears relevant for the present purpose.

As soon as the electrically conductive connections have been reached through the bores to the corresponding conductor tracks 5 on the cover 3 and the bottom surface 4, the electrical conductor tracks are produced on these latter two parts by a customary photo-etching process by placing the unnecessary conductive areas on them be removed from both surfaces. The conductor tracks can also be selectively printed or stamped on. Thereafter, the two surfaces of the cover 3 and the bottom surface 4 that carry the conductor strips are provided with a synthetic resin coating in order to mechanically protect these surfaces, which can be done in an immersion bath. However, care must be taken to ensure that the contact surfaces 9 (connection pads) for the coils 6 and 7 remain free of plastic coating, which is achieved, for example, by a previous lamination. This lamination is then removed and the entire plate is drawn through a solder bath, as a result of which these connection pads 9 protrude slightly as tin soldering feet, so that the later toroidal transformer is designed as an SMD module.

Then the 400 toroidal transformers, which are in the Matrix plate still connected, electrically tested, whereby possibly damaged transformers are provided with a color dot.

After testing, the matrix plate is sawn to separate the toroidal core transformers.

Depending on the hole diameter used for the plated-through holes, it may be necessary to clean the holes before inserting the electrical conductor. For this purpose, for example, a plasma cleaning process is available, as described, for example, in the magazine "productronic 1/2 - 1988, pages 71-72".

The embodiment shown in FIG. 3 differs from the embodiment of FIGS. 1 and 2 in that the cover 3 has been omitted. The bottom part 4, as is clear from the explanation of FIG. 4, is also configured differently; it has a continuous opening for the magnetic core, which is filled with casting resin. Otherwise, the same reference numerals are used for the same parts as in FIGS. 1 and 2. The conductor tracks 5 on the top 10 and the bottom 11 of the base body 1 are located on films 12 made of polyimide.

Polyimide films are sold under the trademark "Kapton". These foils are highly heat-resistant, so they can withstand high temperatures, have no melting temperature, they only carbonize at approx. 800 ^o C, and have a very high electrical resistance. With these properties, they serve as a heat buffer during the hardening of the casting resin and the subsequent cooling.

A manufacturing method for a toroidal core transformer according to FIG. 3 is described below with reference to FIG. 4. If the same or corresponding procedural measures are to be applied as for the core transformer according to FIGS. 1 and 2, e.g. The explanation is not repeated for the production of the bores, the conductor tracks on the surfaces of the base body, the metallizations in the bores or the end pads.

First, one or more sheets of castable epoxy resin with the desired dimensions (length, width, thickness) are cast in a vacuum and cured at approx. 120 ^° C. The recess 13 is shown in the drawing by dashed lines, because due to the subsequent joint curing of the base body 1 and the filling 15 made of the same casting resin, a transition is practically no longer recognizable. The recess 13 for the magnetic cores 2 (e.g. made of ferromagnetic ceramic material) are positioned exactly according to the number of transducers to be produced as a matrix, for example in the case of a plate with the dimensions 16 cm x 16 cm 400 recesses 13, and drilled through the plate or for example for Double-hole cores milled. In addition, two holes for reference holes are drilled at defined points. However, the plate can also consist of thermoplastic material, for example of polyamide, which has a particularly low epsilon value.

The magnetic cores 2 to be inserted into the recesses 13 are checked electrically and for dimensional accuracy and then inserted into the recesses 13 of the plate, which rests on a flat, heated surface, for example a glass plate, after a small amount of casting resin has been filled into the recesses 13 beforehand , which in particular can be carried out fully automatically. The interior of the magnetic cores 2 is then coated with the same resin filled out. Since the thickness of the plate is chosen to be slightly larger, for example by 0.5 mm, than the height of the magnetic cores 2, thin insulating layers 14 are produced from the same casting resin as the filling 15 in the interior of the magnetic cores 2. The casting resin for the interior of the magnetic cores 2 can also be filled with ferrite powder in order to influence the electrical properties of the entire structure in the desired manner.

The plate prepared in this way is then dried at 60 ° C. and then cured at 12 ° C. If necessary, the hardened plate is subjected to a grinding process in order to ensure the plane parallelism required for further processing.

After a cleaning operation with degreasing and dirt-removing agents, it is recommended to dry the plate in an oven at 100 ^° C. Then composite films are applied to each side, which have also been cleaned well and consist of polyimide film of the type described above (25 m thick) and copper coating (17 µm thick). This is done by rolling the composite films.

Finally, the structure is clamped between two plates, dried and hardened again.

The plate is then clamped with its reference holes onto a device with which the holes 16 for the plated-through holes are produced, in particular drilled, according to the predetermined pattern, taking into account the number and position of the turns and windings of the individual coils.

This predetermined pattern, which is to be referred to as the layout, becomes manufactured by computer control and has the taps required for the required number of turns of the desired windings and also contains the masks for the later production of the conductor tracks 5.

The plates are then plated through by producing 16 metal coatings on the inner surfaces of the holes. Photoresist is then applied to the copper layers of the upper side 10 and the lower side 11, the pattern for the conductor tracks is generated using the layout, exposed and etched in a manner known per se, so that the conductor tracks 5 are formed.

In this way, a plate is produced with a large number of RF magnet coil arrangements, which can already be tested electrically in this state. The individual arrangements are then separated by means of a circular saw by cuts along predetermined lines.

If necessary, the individual components can also be soldered to a body specially manufactured for SMD circuits and also provided with a protective cap and are then ready for the final test.

Claims (20)

RF magnet coil arrangement in chip design, containing an annular magnetic core embedded in plastic material and at least one winding made of at least one turn, which winding is led through the magnetic core, the turns consisting of conductor track parts running parallel to the end face of the magnetic core and running parallel to the axis of the magnetic core conductor track parts inserted in the investment plastic are assembled,

characterized by the characteristics

a) the embedding plastic forms an electrically insulating base body (1) which is adapted to the dimensions of the chip and which is provided with an annular recess which corresponds to the size of the magnetic core (2) and does not completely penetrate the base body, b) the magnetic core (2) is located in the recess, at least the interior of which is filled with plastic, c) a cover (3) placed on the base body (1) and the bottom side (4) of the base body (1) have electrical conductor tracks (5), the ends of which each connect two points, the projection (in the direction of the axis of the magnetic core) lie inside and outside the magnetic core (2), with a point in the cover part being aligned with a point in the base part in the projection and the points aligned with one another being connected to one another by bores which are filled with electrically conductive material (8) or at least on their Walls are covered with electrically conductive material and thereby electrically connect two aligned points, d) the conductor track parts (5) on the cover (3) and on the bottom side (4) form the windings of the windings of the at least one winding (coils 6, 7) in a corresponding arrangement together with the metallizations (8) in the bores. RF magnet coil arrangement in chip design, containing an annular magnetic core embedded in plastic material and at least one winding made of at least one turn, which winding is guided through the magnetic core, the turns consisting of parts of the conductor strip running parallel to the end face of the magnetic core and of parallel and parallel to the axis of the magnetic core parts of the conductor inserted in the plastic are composed

characterized by the characteristics

a) the embedding plastic forms an electrically insulating base body (1) which is adapted to the dimensions of the chip and which is provided with an annular recess (13) corresponding to the size of the magnetic core (2), which completely penetrates the base body with its entire clear width, b) the magnetic core (2) is located in the recess, at least the interior of which is filled with plastic (15), c) the top (10) and the bottom (11) of the base body (1) have electrical conductor tracks (5), the ends of which each connect two points, the projection (in the direction of the axis of the magnetic core) inside and outside of the magnetic core (2 ) are in each case one point of a large end face with a point in the opposite large end face in the projection and the aligned points are connected to one another by bores which are filled with electrically conductive material or at least coated on their walls with electrically conductive material are and thus electrically connect two points aligned with each other, d) the conductor track parts (5) on the top (10) and the bottom (11) form the windings of the at least one winding (coils 6, 7) in a corresponding arrangement together with the metallizations in the bores. RF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the conductor tracks (5) are each etched out of a copper foil, which are each on a foil (12) made of polyimide, which is highly heat-resistant and has no melting temperature (Kapton film) is applied, which is arranged between the respective surface of the base body (1) and the copper foil. HF magnet coil arrangement in chip design according to claim 1, characterized in that the bores through the cover (3) are characterized in the conventional manner, through-plated through methods and are soldered to the electrically conductive connections in the bores in the base body (1). RF magnet coil arrangement in chip design according to claim 4, characterized in that the soldering material used has a higher melting point of characterized, at least 300 C, than the usual soldering material with which components are soldered to electrical circuit boards. RF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the base body (1) consists of a thermoplastic, in which the recesses (13) for the magnetic cores (2) are thermally produced. RF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the base body (1) consists of a plate in which a plurality of recesses (13) is provided in a matrix form in order to accommodate a corresponding plurality of toroidal core transformers train at the same time, and that these toroidal transformers are then separated by conventional separating cuts. RF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the base body (1) consists of hardened casting resin, characterized in that the spaces between the base body (1) and the magnetic core (2) and the interior of the magnetic core (2 ) are filled with the same casting resin and that the casting resin of the base body (1) with the filling casting resin (15) form a homogeneous body by curing together. HF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the casting resin is an epoxy resin, which preferably hardens at, approximately 120 C, RF magnet coil arrangement in chip design according to claim 1 or 2, characterized in that the filler resin is filled with ferrite powder.
featured, Method for producing an RF magnet coil arrangement in chip design according to claim 1, 1,

characterized by the process steps
characterized by the process steps

a) equipping the base body provided with at least one recess with a magnetic core or with a plurality of magnetic cores, b) applying the lid, c) drilling the holes, d) Filling the holes with electrically conductive material. A method for producing an RF magnetic coil arrangement in chip design according to claim 11,

characterized by the process steps

a) equipping an electrically insulating base plate with the magnetic core or cores, b) applying electrically conductive material to the base plate and producing column-shaped conductors on the base plate with a length which corresponds to the axial dimension of the magnetic core, around the magnetic core and within the magnetic core, c) filling the space between these conductor columns with electrically insulating material up to the height of the magnetic core, d) closing off the body thus formed with a lid, e) previous or subsequent formation of conductor tracks on the outer surface of the cover and the bottom surface of the base plate with plated-through holes up to the ends of the conductor columns which are still to be formed or have already been formed, f) electrical connection of the plated-through holes to the conductor columns to create complete coils. A method according to claim 12, characterized in that the application according to characterized step b) is carried out with a vapor deposition process, preferably with silver. A method according to claim 13, characterized in that the method is carried out in a step-by-step manner, in that individual layers are vapor-deposited or printed on up to a maximum of 0.1 mm and then subsequently thermally annealed. A method according to claim 12, characterized in that the application according to characterized step b) is carried out by whisker formation using an electrically conductive material. A method for producing an RF magnetic coil arrangement in chip design according to claim 2,

characterized by the process steps

a) a prefabricated plate made of casting resin is provided with a matrix of a plurality of through openings and at least two reference openings resulting in the recess and placed on a flat, heated surface, after which casting resin is filled into each recess in an amount which corresponds to the volume of the later the magnetic core to be used, b) electrical and magnetically tested ring magnetic cores made of ferrite material are inserted into the openings, empty spaces which may still be present, in particular in the interior of the magnetic cores, are filled with casting resin, c) drying the plate thus prepared at 60 C and then curing at 120 C, d) if necessary, the large areas of the plates are ground plane-parallel, e) applying a cleaned composite film (25 m thick) made of a polyimide film which is heat-resistant and has no melting temperature (Kapton film) and copper (17 m thick) on the plane-parallel surfaces of the plate, f) drying the prepared plate again, clamped between two heating plates, at 60 C and then curing at 120 C, g) a defined arrangement of the plate on a device using the reference openings as a centering aid and computer-controlled creation of the holes for the through-plating in accordance with a predetermined pattern that takes into account the desired number of turns, h) producing the plated-through holes in the bores by galvanic deposition of metal (copper) on the inner walls of the bores by methods known per se, i) Generating - the conductor tracks that connect the metallizations in the holes according to the guidance required for the windings of the windings, - the contact surfaces for connecting the windings to the printed SMD circuit, - and the conductor tracks that connect the ends of the respective windings connect to the contact surfaces, in accordance with the predetermined pattern that is also valid for process step g), by etching the copper foil according to methods known for the production of printed circuits, j) automatic electrical testing of the finished transformer and before or after dividing the plate into the individual transformers, in particular by sawing along predetermined dividing lines, Modification of the method according to claim 16, characterized in that a plate made of thermoplastic is used instead of a plate made of casting resin and the spaces in the openings between the magnetic cores and the plate are filled with hardenable casting resin. A method according to claim 11 or 12, characterized in that the electrical through-plating characterized by the bores is carried out using a galvanic method. Method according to Claim 11, 12 or 16, characterized in that any air characterized in this way is removed from the bores by applying negative pressure. A method according to claim 11, 12 or 16, characterized in that the electroplating liquid characterized is pressed into the bores by squeeze rollers.

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