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EP0502940B1 - Composite magnetic sheet material and fabrication method - Google Patents

Composite magnetic sheet material and fabrication method Download PDF

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Publication number
EP0502940B1
EP0502940B1 EP91900269A EP91900269A EP0502940B1 EP 0502940 B1 EP0502940 B1 EP 0502940B1 EP 91900269 A EP91900269 A EP 91900269A EP 91900269 A EP91900269 A EP 91900269A EP 0502940 B1 EP0502940 B1 EP 0502940B1
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EP
European Patent Office
Prior art keywords
ferromagnetic
support film
magnetic
material according
sheets
Prior art date
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Expired - Lifetime
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EP91900269A
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German (de)
French (fr)
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EP0502940A1 (en
Inventor
Jean-Marie Fontaine
Arnaud Varoquaux
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Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
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Commissariat a lEnergie Atomique CEA
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    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F41/00—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties
    • H01F41/14—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates
    • H01F41/20—Apparatus or processes specially adapted for manufacturing or assembling magnets, inductances or transformers; Apparatus or processes specially adapted for manufacturing materials characterised by their magnetic properties for applying magnetic films to substrates by evaporation
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
    • H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
    • H01F10/12—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being metals or alloys
    • H01F10/13—Amorphous metallic alloys, e.g. glassy metals
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/08—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers
    • H01F10/10—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition
    • H01F10/12—Thin magnetic films, e.g. of one-domain structure characterised by magnetic layers characterised by the composition being metals or alloys
    • H01F10/13—Amorphous metallic alloys, e.g. glassy metals
    • H01F10/132—Amorphous metallic alloys, e.g. glassy metals containing cobalt
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/26—Thin magnetic films, e.g. of one-domain structure characterised by the substrate or intermediate layers
    • H01F10/28—Thin magnetic films, e.g. of one-domain structure characterised by the substrate or intermediate layers characterised by the composition of the substrate
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F10/00—Thin magnetic films, e.g. of one-domain structure
    • H01F10/26—Thin magnetic films, e.g. of one-domain structure characterised by the substrate or intermediate layers
    • H01F10/30—Thin magnetic films, e.g. of one-domain structure characterised by the substrate or intermediate layers characterised by the composition of the intermediate layers, e.g. seed, buffer, template, diffusion preventing, cap layers

Definitions

  • the present invention relates to a method of manufacturing a composite magnetic material in sheets having a high magnetic permeability at high frequency and a low density.
  • This material can be used in magnetic heads for high frequency magnetic recording due to its high magnetic stability; as a core for very high frequency winding and transformer; as an electromagnetic filter or as an electromagnetic shielding used in particular in the fields of telecommunications and data processing (shielding of complex circuits, computers, etc.); as a microwave absorber in an anechoic chamber (chamber without echo) intended for experimental studies or also as an absorbent material in microwave ovens. In this latter application, the material is intended to be placed on the internal face of the oven door.
  • Composite materials make it possible to obtain materials with magnetic permeability and electrical permittivity suitable for each type of application.
  • the magnetic material is intended to equip anechoic chambers.
  • the known materials currently used for this application consist of pyramidal patterns or cellular structures having a thickness of several tens of centimeters and a low surface density, ranging from 1 to 5 kg / m2. Unfortunately, this type of material is limited to a range of short wavelengths.
  • microwave absorbent materials which are in the form of thin layers, of thickness less than a few centimeters, made with dense materials such as ferrite or from the dispersion of these dense materials in a suitable organic binder.
  • This type of material has the disadvantage of being heavy (> 10 kg / m2); these materials have a low magnetic permeability resulting in the large thicknesses and the associated masses.
  • this document teaches the production of etching lines of 10 micrometers for a stack of layers with a thickness of 70 to 600 micrometers.
  • the width of the etching line is at least equal to one to two times the thickness of the stack (or layers) to be etched.
  • the object of the invention is precisely the manufacture of a new magnetic composite material in sheets which makes it possible to remedy the various drawbacks given above.
  • this material has a low density and a high magnetic permeability.
  • its manufacturing process is industrially feasible and its implementation relatively easy.
  • the material simultaneously combines magnetic performance and high production rates.
  • the subject of the invention is a process for manufacturing a composite magnetic material in sheets, the number of which varies from at least 50 sheets attached to 500 sheets attached, consisting of forming each sheet by passing a support film of polymer, mechanically and thermally resistant and with a thickness of less than 10 ⁇ m, in a deposition enclosure in which there is a residual vacuum ⁇ 10 et Pa and by continuously depositing on one at least of the faces of the film in movement a layer 300nm to 10 ⁇ m thick of an amorphous ferromagnetic compound and to assemble the sheets obtained, the density d and the magnetic permeability ⁇ of the composite magnetic material being such that 5 ⁇ ⁇ / d ⁇ 100.
  • a ferromagnetic deposit can be formed on each face of the support film.
  • several support films each coated with their ferromagnetic deposit (s), made integral by an adhesive film, can be used.
  • the ferromagnetic deposits can be made of the same material or of different materials so as to modify the magnetic permeability spectrum.
  • This sheet material unlike that of the prior art FR-A-2 620 853, does not break down.
  • the volume percentage of metal relative to the total volume of the composite material is less than 50%, which corresponds to a Vm / Vi ratio ⁇ 10 and is generally chosen in the range from 10 to 20%, which corresponds at a ratio 2 ⁇ Vm / Vi ⁇ 4.
  • This percentage by volume of metal is lower than that of the material which is the subject of document FR-A-2 620 853, containing from 50 to 90% by volume of metal.
  • the permeability of the composite material depends on that of the ferromagnetic metal used and on its concentration. Values of a few hundred, at 100 MHz, can be reached with a 3.5 density composite material.
  • ferromagnetic material with high magnetic permeability ensures good material stability up to frequencies of a few hundred MHz, or even up to 1 GHz.
  • the ferromagnetic materials which can be used in the invention are those which have a magnetic permeability greater than 300, a 4 ⁇ Ms ⁇ 0.5T, with Ms representing the magnetization at saturation of the ferromagnetic material, as well as an anisotropy field.
  • magnetic Ha ranging from 0 to 2500 A / m.
  • the ferromagnetic materials which can be used in particular in the invention are amorphous compounds containing a high amount of cobalt, that is to say containing at least 75% of cobalt atoms.
  • ferromagnetic materials which can be used in the invention mention may be made of Co87Nb 11.5 Zr 1.5 , Co89Nb 6.5 Zr 4.5 , Co89Zr11, Co93Zr7, or Co79Zr10Mo9Ni2.
  • the thickness of the ferromagnetic deposits depends on the application envisaged.
  • a microwave absorbing material in the case of anechoic chambers or microwave ovens
  • the higher the frequencies to be absorbed the smaller the thickness of each ferromagnetic deposit.
  • each deposit ferromagnetic is less than the skin thickness of the frequencies of use.
  • ferromagnetic deposits of less than 2 micrometers are used.
  • frequencies of 10 MHz a few micrometers (around 5-6) can be used for ferromagnetic deposition.
  • the ferromagnetic layers have a thickness ranging from 300 nm to 10 micrometers.
  • the support film must be thermally stable and in particular be stable between 150 and 300 ° C.
  • this film must not be a thermoplastic.
  • this film must be thin, that is to say less than 10 micrometers. Films from 0.8 to 1.5 microns can be used.
  • the support film must be mechanically resistant and in particular resistant to tearing.
  • Support films having a tear strength ranging from 18 to 50 kg / mm2 can be used.
  • polyimides such as Kapton (R)
  • polycarbonates such as polyesters, polyethylene terephthalates such as Mylar (R) or also polyetheretherketone such as Peek (R ) .
  • polyetheretherketone such as Peek (R ) .
  • the ferromagnetic deposit (s) may each be coated with a thin layer electrical insulation.
  • electrically insulating materials which can be used in the invention, mention may be made of quartz, glass, silica, amorphous silicon, aluminum, silicon nitride, zinc sulfide. These layers of electrical insulator can have a thickness ranging from 10 to 100 nm.
  • the subject of the invention is a method of manufacturing the composite magnetic material as described above. This process consists in running the support film through a deposition enclosure in which there is a residual vacuum ⁇ 10 ⁇ 5 Pa and in continuously depositing a layer of a ferromagnetic compound on at least one of the faces of the film in movement.
  • the vacuum deposition of ferromagnetic layers on the moving support film is relatively simple to perform and is compatible with a high production rate.
  • the magnetic material comprises a ferromagnetic deposit equipped with etching lines
  • these etching lines are carried out continuously using a laser beam on the ferromagnetic deposit in movement.
  • This engraving technique has a low cost and is compatible with a high production rate. In addition, it ensures a wide dynamic range of etching width adjustable between 5 and 500 micrometers, depending on the thickness of the layers to be etched.
  • Laser engraving while scrolling requires the use of a laser whose wavelength is not absorbed by the support film.
  • the support film must be perfectly transparent at the wavelength of the chosen laser.
  • an infrared laser is ideal for a Mylar (R) backing film.
  • the ferromagnetic strips or blocks it is also possible to form directly, during the deposition of the ferromagnetic material, the ferromagnetic strips or blocks, by selective deposition using a mask.
  • the technique known as "lift off” can be used.
  • This technique consists of forming a photolithographic resin mask on the support film, the resinc masking the regions of the film intended to be devoid of ferromagnetic material, depositing a ferromagnetic layer on the entire structure under vacuum and then removing the mask. resin, the ferromagnetic material surmounting the resin being removed at the same time as the latter.
  • a weak magnetic field (a few hundred A / m) is applied parallel to the plane of the support film.
  • Annealing temperatures are between 100 and 300 ° C and the amplitude of the magnetic field varies from 10 to 100 kA / m.
  • the speed of rotation is between 2 ⁇ and 20 ⁇ rad / m.
  • the composite material shown in Figure 1 is a single sheet material. It comprises a polymeric film 2 thermally resistant between 150 and 300 ° C and having a tear strength ranging from 18 to 50 kg / mm2.
  • This polymeric film 4 has a thickness of 1 to 4 micrometers and is provided on its upper face 4 with a layer 6 of a ferromagnetic material having a magnetic permeability greater than 300 and in particular greater than 600 and a thickness of 300 to 800 nm .
  • This layer 4 consists of square blocks 8 having a surface of 2 to 10 mm2, separated by etching lines 10 400 to 2000 nm wide depending on the thickness of the ferromagnetic layer.
  • the density d of the composite material and its magnetic permeability ⁇ are linked by the equation 5 ⁇ ⁇ / d ⁇ 100 and in particular by the equation 10 ⁇ ⁇ / d ⁇ 100.
  • the ferromagnetic layer 6 is continuously deposited by evaporation or spraying under vacuum on the supporting film 2 in movement.
  • the deposition of the ferromagnetic layer 6 takes place under a residual vacuum ⁇ at 10 ⁇ 5 Pa.
  • the speed of movement of the film is linked to the deposition technique used.
  • the deposition 6 of ferromagnetic material is done by simultaneously applying a magnetic field of a few hundred A / m (about 10 kA / m) parallel to the plane of the film 2.
  • first ferromagnetic bands are then cut out in layer 6, parallel to the x direction. Then a second cutting of the ferromagnetic deposit 6 is carried out, in the direction y perpendicular to the direction x.
  • This laser is an infrared laser having a wavelength of 1060 nm for a support film 2 made of Mylar (R) .
  • an annealing is carried out between 150 and 300 ° C., in the presence of a magnetic field. rotation or fixed of a few hundred A / m (80 kA / m) contained in the plane of the support film 2.
  • the ferromagnetic deposit 6a can also, according to the invention, consist of ferromagnetic strips 12 as shown in FIG. 2.
  • a second ferromagnetic layer 14 on the face 16, opposite the face 4, of the support film.
  • This layer 14 can consist of parallel strips 18 or paving stones.
  • the etching lines 20, 22 (FIG. 2) of the upper 6a and lower 14 ferromagnetic deposits can be offset.
  • FIGS. 1 or 2 Depending on the application envisaged, several structures or sheets are stacked and assembled as shown in FIGS. 1 or 2.
  • These insulating layers have a thickness of 10 to 100 nm. Their etching lines are produced at the same time as those of the ferromagnetic deposits, with a laser beam and are therefore coincidental.
  • FIG 4 there is shown a stack of several structures 25, or sheets.
  • the number of sheets 25 can range from 50 to 500.
  • the assembly of these sheets is obtained using an adhesive joint.
  • the adhesive used is a fluid polyester resistant to temperature.
  • the stacking of these different sheets can be carried out by winding, draping or any other known technique.
  • the adhesive film is obtained by spraying, which makes it possible to deposit thicknesses of adhesive that are largely submicron, typically 0.2 microns.
  • This deposition is carried out, under a plane magnetic field of 800 A / m, in a BVT cathode sputtering frame in which a residual vacuum of less than 10 a Pa has been carried out.
  • a 50 nm thick deposit of SiO2 is then carried out on each ferromagnetic deposit by PECVD (chemical vapor deposition assisted by a plasma).
  • etching lines of 100 micrometers are then made using a 1060 nm YAG laser. wide, for the SiO2 layers formed of pavers of 3 mm side. This engraving is carried out with a scrolling of the sheet of 0.15 m / s.
  • the composite material obtained has a magnetic permeability of 90 and a density of 2, ie a ⁇ / d ratio of 45.
  • Example 2 differs from example 1 by the use of 50 glued sheets, each consisting of a single deposit of Co87Nb 11.5 Zr 1.5 of 400 nm on the Mylar film, covered with a thin layer of 20 nm of SiO2.
  • the etching lines are the same as in Example 1.
  • This composite material has a density of 2 and a ⁇ / d ratio of 7 to 300 MHz.
  • the composite material is formed of 50 glued sheets, each consisting of a 400 nm deposit of Co87Nb 11.5 Zr 1.5 on both sides of a 3.5 micrometers film of Mylar (R) thick, this deposit being covered with a thin layer of 20 nm of SiO2.
  • the etching lines are the same as in Example 1.
  • This composite material has a density of 2.5 and a ⁇ / d ratio of 10 to 300 MHz.
  • Figures 5 and 6 clearly show that the magnetic permeability of the composite materials of the invention remains stable over large wavelength ranges.
  • the table below indicates the ⁇ / d ratio of the composite materials of Examples 1, 2 and 3 for different frequencies of incident electromagnetic wave, as well as that of a traditional ferrite material.

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Abstract

The invention relates to a composite magnetic sheet material comprising at least one thin support film of polymer, which is mechanically and thermally resistant, coated on at least one of its faces with a thin deposit of a ferromagnetic amorphous compound having a magnetic permeability higher than 30, the density d and the permeability of the composite magnetic material being such that 5 « ν/d « 100.

Description

La présente invention a pour objet un procédé de fabrication d'un matériau magnétique composite en feuilles ayant une forte perméabilité magnétique en haute fréquence et une faible densité.The present invention relates to a method of manufacturing a composite magnetic material in sheets having a high magnetic permeability at high frequency and a low density.

Ce matériau peut être utilisé dans des têtes magnétiques pour enregistrement magnétique haute fréquence du fait de sa grande stabilité magnétique ; comme noyau pour bobinage et transformateur à très haute fréquence ; comme filtre électromagnétique ou comme blindage électromagnétique utilisé notamment dans les domaines des telécommunications et de l'informatique (blindage de circuits complexes, d'ordinateurs, etc.) ; comme absorbeur des micro-ondes dans une chambre anéchoïque (chambre sans écho) destinée à des études expérimentales ou encore comme matériau absorbant dans les fours à micro-ondes. Dans cette dernière application, le matériau est destiné à être placé sur la face interne de la porte du four.This material can be used in magnetic heads for high frequency magnetic recording due to its high magnetic stability; as a core for very high frequency winding and transformer; as an electromagnetic filter or as an electromagnetic shielding used in particular in the fields of telecommunications and data processing (shielding of complex circuits, computers, etc.); as a microwave absorber in an anechoic chamber (chamber without echo) intended for experimental studies or also as an absorbent material in microwave ovens. In this latter application, the material is intended to be placed on the internal face of the oven door.

Les matériaux composites permettent d'obtenir des matériaux à perméabilité magnétique et à permittivité électrique adaptées pour chaque type d'application.Composite materials make it possible to obtain materials with magnetic permeability and electrical permittivity suitable for each type of application.

Plus spécifiquement, le matériau magnétique est destiné à équiper des chambres anéchoïques.More specifically, the magnetic material is intended to equip anechoic chambers.

Les matériaux connus, actuellement utilisés pour cette application, sont constitués de motifs pyramidaux ou de structures alvéolaires présentant une épaisseur de plusieurs dizaine de centimètres et une densité surfacique faible, allant de 1 à 5 kg/m². Malheureusement, ce type de matériau est limité à une gamme de faibles longueurs d'onde.The known materials currently used for this application consist of pyramidal patterns or cellular structures having a thickness of several tens of centimeters and a low surface density, ranging from 1 to 5 kg / m². Unfortunately, this type of material is limited to a range of short wavelengths.

Par ailleurs, il est connu des matériaux absorbant les micro-ondes se présentant sous forme de couches minces, d'épaisseur inférieure à quelques centimètres, réalisées avec des matériaux denses tels que la ferrite ou à partir de la dispersion de ces matériaux denses dans un liant organique approprié. Ce type de matériau présente l'inconvénient d'être lourd (>10 kg/m²) ; ces matériaux présentent une faible perméabilité magnétique entraînant les fortes épaisseurs et les masses associées.Furthermore, microwave absorbent materials are known which are in the form of thin layers, of thickness less than a few centimeters, made with dense materials such as ferrite or from the dispersion of these dense materials in a suitable organic binder. This type of material has the disadvantage of being heavy (> 10 kg / m²); these materials have a low magnetic permeability resulting in the large thicknesses and the associated masses.

Pour remédier à ces inconvénients, le demandeur a envisagé de fabriquer un matériau magnétique composite constitué d'une alternance de couches ferromagnétiques amorphes et de couches électriquement isolantes, chaque couche de matériau ferromagnétique étant formée de plusieurs pavés séparés les uns des autres par des joints électriquement isolants. Ce principe est décrit dans le document FR-A-2 620 853. Malheureusement, le matériau magnétique décrit dans ce document est actuellement pratiquement irréalisable et son procédé de fabrication extrêmement difficile à mettre en oeuvre.To remedy these drawbacks, the applicant has considered manufacturing a composite magnetic material consisting of an alternation of amorphous ferromagnetic layers and electrically insulating layers, each layer of ferromagnetic material being formed of several blocks separated from each other by electrically seals insulators. This principle is described in document FR-A-2 620 853. Unfortunately, the magnetic material described in this document is currently practically impracticable and its manufacturing process extremely difficult to implement.

En particulier, ce document enseigne la réalisation de traits de gravure de 10 micromètres pour un empilement de couches d'une épaisseur de 70 à 600 micromètres. Or, actuellement, même avec un procédé de gravure par laser, la largeur du trait de gravure est au minimum égale à une à deux fois l'épaisseur de l'empilement (ou couches) à graver.In particular, this document teaches the production of etching lines of 10 micrometers for a stack of layers with a thickness of 70 to 600 micrometers. However, currently, even with a laser etching process, the width of the etching line is at least equal to one to two times the thickness of the stack (or layers) to be etched.

L'invention a justement pour objet la fabrication d'un nouveau matériau magnétique composite en feuilles permettant de remédier aux différents inconvénients donnés ci-dessus. En particulier, ce matériau présente une densité faible ainsi qu'une forte perméabilité magnétique. En outre, son procédé de fabrication est réalisable industriellement et sa mise en oeuvre relativement aisée.The object of the invention is precisely the manufacture of a new magnetic composite material in sheets which makes it possible to remedy the various drawbacks given above. In particular, this material has a low density and a high magnetic permeability. In addition, its manufacturing process is industrially feasible and its implementation relatively easy.

Le matériau allie simultanément des performances magnétiques et des cadences de fabrication élevées.The material simultaneously combines magnetic performance and high production rates.

De façon plus précise, l'invention a pour objet un procédé de fabrication d'un matériau magnétique composite en feuilles dont le nombre varie d'au moins 50 feuilles solidaires à 500 feuilles solidaires, consistant à former chaque feuille en faisant défiler un film support de polymère, résistant mécaniquement et thermiquement et d'épaisseur inférieure à 10µm, dans une enceinte de dépôt dans laquelle règne un vide résiduel <10⁻⁵ Pa et en déposant en continu sur l'une au moins des faces du film en défilement une couche de 300nm à 10µm d'épaisseur d'un composé amorphe ferromagnétique et à assembler les feuilles obtenues, la densité d et la permabilité magnétique µ du matériau magnétique composite étant telles que 5≦µ/d≦100.More specifically, the subject of the invention is a process for manufacturing a composite magnetic material in sheets, the number of which varies from at least 50 sheets attached to 500 sheets attached, consisting of forming each sheet by passing a support film of polymer, mechanically and thermally resistant and with a thickness of less than 10 μm, in a deposition enclosure in which there is a residual vacuum <10 et Pa and by continuously depositing on one at least of the faces of the film in movement a layer 300nm to 10µm thick of an amorphous ferromagnetic compound and to assemble the sheets obtained, the density d and the magnetic permeability µ of the composite magnetic material being such that 5 ≦ µ / d ≦ 100.

Selon l'invention un dépôt ferromagnétique peut être formé sur chaque face du film support. En outre, suivant l'application envisagée plusieurs films supports revêtus chacun de leur(s) dépôt(s) ferromagnétique(s), rendus solidaires par un film de colle, peuvent être utilisés.According to the invention a ferromagnetic deposit can be formed on each face of the support film. In addition, depending on the application envisaged, several support films each coated with their ferromagnetic deposit (s), made integral by an adhesive film, can be used.

Dans cet empilement, les dépôts ferromagnétiques peuvent être réalisés en un même matériau ou en des matériaux différents de façon à modifier le spectre de perméabilité magnétique.In this stack, the ferromagnetic deposits can be made of the same material or of different materials so as to modify the magnetic permeability spectrum.

Ce matériau en feuilles, contrairement à celui de l'art antérieur FR-A-2 620 853 ne se défeuille pas.This sheet material, unlike that of the prior art FR-A-2 620 853, does not break down.

Le pourcentage en volume de métal par rapport au volume total du matériau composite est inférieur à 50%, ce qui correspond à un rapport Vm/Vi<10 et est en général choisi dans l'intervalle allant de 10 à 20%, ce qui correspond à un rapport 2≦Vm/Vi≦4.The volume percentage of metal relative to the total volume of the composite material is less than 50%, which corresponds to a Vm / Vi ratio <10 and is generally chosen in the range from 10 to 20%, which corresponds at a ratio 2 ≦ Vm / Vi ≦ 4.

Ce pourcentage en volume de métal est inférieur à celui du matériau objet du document FR-A-2 620 853, contenant de 50 à 90% en volume de métal.This percentage by volume of metal is lower than that of the material which is the subject of document FR-A-2 620 853, containing from 50 to 90% by volume of metal.

La perméabilité du matériau composite dépend de celle du métal ferromagnétique utilisé et de sa concentration. Des valeurs de quelques centaines, à 100 MHz, peuvent être atteintes avec un matériau composite de 3,5 de densité.The permeability of the composite material depends on that of the ferromagnetic metal used and on its concentration. Values of a few hundred, at 100 MHz, can be reached with a 3.5 density composite material.

L'utilisation de matériau ferromagnétique de forte perméabilité magnétique assure une bonne stabitité des matériaux jusqu'à des fréquences de quelques centaines de MHz, voire même jusqu'à 1 GHz.The use of ferromagnetic material with high magnetic permeability ensures good material stability up to frequencies of a few hundred MHz, or even up to 1 GHz.

De façon générale, les matériaux ferromagnétiques utilisables dans l'invention sont ceux qui présentent une perméabilité magnétique supérieure à 300, un 4πMs≧0,5T, avec Ms représentant l'aimantation à saturation du matériau ferromagnétique, ainsi qu'un champ d'anisotropie magnétique Ha allant de 0 à 2500 A/m.In general, the ferromagnetic materials which can be used in the invention are those which have a magnetic permeability greater than 300, a 4πMs ≧ 0.5T, with Ms representing the magnetization at saturation of the ferromagnetic material, as well as an anisotropy field. magnetic Ha ranging from 0 to 2500 A / m.

Les matériaux ferromagnétiques utilisables en particulier dans l'invention sont des composés amorphes contenant une quantité élevée de cobalt, c'est-à-dire contenant au moins 75% d'atomes de cobalt. Comme matériaux ferromagnétiques utilisables dans l'invention, on peut citer le Co₈₇Nb11,5Zr1,5, le Co₈₉Nb6,5Zr4,5, le Co₈₉Zr₁₁, Co₉₃Zr₇, ou le Co₇₉Zr₁₀Mo₉Ni₂.The ferromagnetic materials which can be used in particular in the invention are amorphous compounds containing a high amount of cobalt, that is to say containing at least 75% of cobalt atoms. As ferromagnetic materials which can be used in the invention, mention may be made of Co₈₇Nb 11.5 Zr 1.5 , Co₈₉Nb 6.5 Zr 4.5 , Co₈₉Zr₁₁, Co₉₃Zr₇, or Co₇₉Zr₁₀Mo₉Ni₂.

L'épaisseur des dépôts ferromagnétiques est fonction de l'application envisagée. En particulier, en tant que matériau absorbant les micro-ondes (cas des chambres anéchoïques ou des fours à micro-ondes), plus les fréquences à absorber sont élevées, plus l'épaisseur de chaque dépôt ferromagnétique est faible.The thickness of the ferromagnetic deposits depends on the application envisaged. In particular, as a microwave absorbing material (in the case of anechoic chambers or microwave ovens), the higher the frequencies to be absorbed, the smaller the thickness of each ferromagnetic deposit.

En général, l'épaisseur de chaque dépôt ferromagnétique est inférieure à l'épaisseur de peau des fréquences d'utilisation. Par exemple pour 100 MHz on utilise des dépôts ferromagnétiques inférieurs à 2-micromètres. En revanche, pour des fréquences de 10 MHz, quelques micromètres (5-6 environ) peuvent être utilisés pour le dépôt ferromagnétiques.In general, the thickness of each deposit ferromagnetic is less than the skin thickness of the frequencies of use. For example, for 100 MHz, ferromagnetic deposits of less than 2 micrometers are used. On the other hand, for frequencies of 10 MHz, a few micrometers (around 5-6) can be used for ferromagnetic deposition.

De façon générale, les couches ferromagnétiques ont une épaisseur allant de 300 nm à 10 micromètres.Generally, the ferromagnetic layers have a thickness ranging from 300 nm to 10 micrometers.

Selon l'invention le film support doit être stable thermiquement et en particulier être stable entre 150 et 300°C. En particulier, ce film ne doit pas être un thermoplastique. En outre, ce film doit être mince, c'est-à-dire inférieur à 10 micromètres. Des films de 0,8 à 1,5 micromètre peuvent être utilisés.According to the invention the support film must be thermally stable and in particular be stable between 150 and 300 ° C. In particular, this film must not be a thermoplastic. In addition, this film must be thin, that is to say less than 10 micrometers. Films from 0.8 to 1.5 microns can be used.

Par ailleurs, le film support doit être résistant mécaniquement et en particulier résistant au déchirement. Des films support ayant une résistance au déchirement allant de 18 à 50 kg/mm² peuvent être utilisés.Furthermore, the support film must be mechanically resistant and in particular resistant to tearing. Support films having a tear strength ranging from 18 to 50 kg / mm² can be used.

Comme film polymérique utilisable dans l'invention, on peut citer les polyimides tels que le Kapton(R), les polycarbonates, les polyesters, les polytéréphtalates d'éthylène glycol tel que le Mylar(R) ou encore les polyétheréthercétone comme le Peek(R).As polymeric film which can be used in the invention, mention may be made of polyimides such as Kapton (R) , polycarbonates, polyesters, polyethylene terephthalates such as Mylar (R) or also polyetheretherketone such as Peek (R ) .

D'excellents résultats sont obtenus avec des films de Mylar(R) ayant une épaisseur de 1,5 micromètre environ.Excellent results are obtained with Mylar (R) films having a thickness of approximately 1.5 micrometers.

Si la forte conductivité des dépôts ferromagnétiques est gênante pour l'application envisagée, celle-ci peut être annulée dans le matériau composite par gravure de bandes ou de pavés dans chaque dépôt ferromagnétique.If the high conductivity of the ferromagnetic deposits is troublesome for the envisaged application, this can be canceled in the composite material by etching strips or blocks in each ferromagnetic deposit.

En outre, le ou les dépôts ferromagnétiques peuvent être revêtus chacun d'une couche mince d'isolant électrique. Comme matériaux électriquement isolants utilisables dans l'invention, on peut citer le quartz, le verre, la silice, le silicium amorphe, l'aluminium, le nitrure de silicium, le sulfure de zinc. Ces couches d'isolant électrique peuvent avoir une épaisseur allant de 10 à 100 nm.In addition, the ferromagnetic deposit (s) may each be coated with a thin layer electrical insulation. As electrically insulating materials which can be used in the invention, mention may be made of quartz, glass, silica, amorphous silicon, aluminum, silicon nitride, zinc sulfide. These layers of electrical insulator can have a thickness ranging from 10 to 100 nm.

L'invention a pour objet un procédé de fabrication du matériau magnétique composite tel que décrit précédemment. Ce procedé consiste à faire défiler le film support dans une enceinte de dépôt dans laquelle règne un vide résiduel < 10⁻⁵ Pa et à déposer en continu sur l'une au moins des faces du film en défilement une couche d'un composé ferromagnétique.The subject of the invention is a method of manufacturing the composite magnetic material as described above. This process consists in running the support film through a deposition enclosure in which there is a residual vacuum <10⁻⁵ Pa and in continuously depositing a layer of a ferromagnetic compound on at least one of the faces of the film in movement.

Le dépôt sous vide de couches ferromagnétiques sur le film support en défilement est relativement simple à réaliser et est compatible avec une grande cadence de fabrication.The vacuum deposition of ferromagnetic layers on the moving support film is relatively simple to perform and is compatible with a high production rate.

Par ailleurs, lorsque le matériau magnétique comporte un dépôt ferromagnétique équipé de traits de gravure, ces traits de gravure sont effectués en continu à l'aide d'un faisceau laser sur le dépôt ferromagnétique en défilement.Furthermore, when the magnetic material comprises a ferromagnetic deposit equipped with etching lines, these etching lines are carried out continuously using a laser beam on the ferromagnetic deposit in movement.

Cette technique de gravure présente un faible coût et est compatible avec une grande cadence de fabrication. En outre, elle assure une grande dynamique de largeur de gravure réglable entre 5 et 500 micromètres, suivant l'épaisseur des couches à graver.This engraving technique has a low cost and is compatible with a high production rate. In addition, it ensures a wide dynamic range of etching width adjustable between 5 and 500 micrometers, depending on the thickness of the layers to be etched.

La gravure par laser, en défilement, nécessite d'utiliser un laser dont la longueur d'onde n'est pas absorbée par le film support. Autrement dit, le film support doit être parfaitement transparent à la longueur d'onde du laser choisi. Par exemple, un laser à infra-rouge convient parfaitement bien pour un film support en Mylar(R).Laser engraving while scrolling requires the use of a laser whose wavelength is not absorbed by the support film. In other words, the support film must be perfectly transparent at the wavelength of the chosen laser. For example, an infrared laser is ideal for a Mylar (R) backing film.

Ainsi, la gravure peut être obtenue par sublimation de la couche ferromagnétique, sans détérioration du film support.Thus, engraving can be obtained by sublimation of the ferromagnetic layer, without deterioration of the support film.

Il est toutefois possible d'effectuer une gravure chimique du dépôt ferromagnétique en utilisant un masque photolithographique.However, it is possible to chemically etch the ferromagnetic deposit using a photolithographic mask.

Conformément à l'invention, il est aussi possible de former directement, lors du dépôt du matériau ferromagnétique, les bandes ou les pavés ferromagnétiques, par dépôts sélectifs à l'aide d'un masque. Par exemple on peut utiliser la technique connue sous le nom de "lift off".According to the invention, it is also possible to form directly, during the deposition of the ferromagnetic material, the ferromagnetic strips or blocks, by selective deposition using a mask. For example, the technique known as "lift off" can be used.

Cette technique consiste à former un masque de résine photolithographique sur le film support, la resinc masquant les régions du film destinées à être dépourvues de matériau ferromagnétique, à déposer sous vide sur l'ensemble de la structure une couche ferromagnétique puis à éliminer le masque de résine, le matériau ferromagnétique surmontant la résine étant éliminé en même temps que cette dernière.This technique consists of forming a photolithographic resin mask on the support film, the resinc masking the regions of the film intended to be devoid of ferromagnetic material, depositing a ferromagnetic layer on the entire structure under vacuum and then removing the mask. resin, the ferromagnetic material surmounting the resin being removed at the same time as the latter.

Afin de fixer l'orientation magnétique des dépôts ferromagnétiques ainsi que d'améliorer la reproductibilité du matériau composite, on applique un champ magnétique faible (quelques centaines d'A/m) parallèlement au plan du film support.In order to fix the magnetic orientation of the ferromagnetic deposits as well as to improve the reproducibility of the composite material, a weak magnetic field (a few hundred A / m) is applied parallel to the plane of the support film.

Enfin, afin d'améliorer la perméabilité magnétique du matériau composite, un recuit sous champ magnétique tournant ou fixe peut être utilisé. Les températures de recuit sont comprises entre 100 et 300°C et l'amplitude du champ magnétique varie de 10 à 100 kA/m.Finally, in order to improve the magnetic permeability of the composite material, annealing under a rotating or fixed magnetic field can be used. Annealing temperatures are between 100 and 300 ° C and the amplitude of the magnetic field varies from 10 to 100 kA / m.

Pour un champ tournant, la vitesse de rotation est comprise entre 2π et 20π rad/m.For a rotating field, the speed of rotation is between 2π and 20π rad / m.

D'autres caractéristiques et avantages de l'invention ressortiront mieux de la description qui va suivre, donnés à titre illustratif et non limitatif, en référence aux dessins annexés :

  • les figures 1 à 4, représentant schématiquement différents modes de réalisation du matériau composite conforme à l'invention, et
  • les figures 5 et 6 sont des courbes donnant les variations de la perméabitité magnétique de deux matériaux composites selon l'invention en fonction de la fréquence de l'onde électromagnétique incidente, exprimée en MHz.
Other characteristics and advantages of the invention will emerge more clearly from the description which follows, given by way of illustration and not limitation, in reference to the accompanying drawings:
  • FIGS. 1 to 4, schematically showing different embodiments of the composite material according to the invention, and
  • FIGS. 5 and 6 are curves giving the variations in the magnetic permeability of two composite materials according to the invention as a function of the frequency of the incident electromagnetic wave, expressed in MHz.

Le matériau composite représenté sur la figure 1 est un matériau monofeuille. Il comporte un film polymérique 2 résistant thermiquement entre 150 et 300°C et ayant une résistance au déchirement allant de 18 à 50 kg/mm². Ce film polymérique 4 a une épaisseur de 1 à 4 micromètres et est pourvu sur sa face supérieure 4 d'une couche 6 en un matériau ferromagnétique ayant une perméabilité magnétique supérieure à 300 et en particulier supérieure à 600 et une épaisseur de 300 à 800 nm. Cette couche 4 est constituée de pavés carrés 8 ayant une surface de 2 à 10 mm², séparés par des traits de gravure 10 de 400 à 2000 nm de large suivant l'épaisseur de la couche ferromagnétique.The composite material shown in Figure 1 is a single sheet material. It comprises a polymeric film 2 thermally resistant between 150 and 300 ° C and having a tear strength ranging from 18 to 50 kg / mm². This polymeric film 4 has a thickness of 1 to 4 micrometers and is provided on its upper face 4 with a layer 6 of a ferromagnetic material having a magnetic permeability greater than 300 and in particular greater than 600 and a thickness of 300 to 800 nm . This layer 4 consists of square blocks 8 having a surface of 2 to 10 mm², separated by etching lines 10 400 to 2000 nm wide depending on the thickness of the ferromagnetic layer.

Selon l'invention, la densité d du matériau composite et sa perméabilité magnétique µ sont liées par l'équation 5≦µ/d≦100 et en particulier par l'équation 10≦µ/d≦100.According to the invention, the density d of the composite material and its magnetic permeability µ are linked by the equation 5 ≦ µ / d ≦ 100 and in particular by the equation 10 ≦ µ / d ≦ 100.

Selon l'invention, on dépose en continu par évaporation ou pulvérisation sous vide la couche 6 ferromagnétique sur le film support 2 en défilement. Le depôt de la couche ferromagnétique 6 se fait sous un vide résiduel < à 10⁻⁵ Pa. La vitesse de défilement du film est liée à la technique de dépôt utilisée.According to the invention, the ferromagnetic layer 6 is continuously deposited by evaporation or spraying under vacuum on the supporting film 2 in movement. The deposition of the ferromagnetic layer 6 takes place under a residual vacuum <at 10⁻⁵ Pa. The speed of movement of the film is linked to the deposition technique used.

Avec une pulvérisation, on utilise un défilement de 10 à 20 cm par minute alors qu'avec une évaporation on peut atteindre des vitesses de l'ordre du mètre par seconde.With a spray, a scroll of 10 to 20 cm per minute is used while with a evaporation we can reach speeds of the order of one meter per second.

Le dépôt 6 de matériau ferromagnétique se fait en appliquant simultanément un champ magnétique de quelques centaines d'A/m (10 kA/m environ) parallèlement au plan du film 2.The deposition 6 of ferromagnetic material is done by simultaneously applying a magnetic field of a few hundred A / m (about 10 kA / m) parallel to the plane of the film 2.

A l'aide d'un faisceau laser on découpe ensuite des premières bandes ferromagnétiques dans la couche 6, parallèles à la direction x. Puis on effectue une seconde découpe du dépôt ferromagnétique 6, selon la direction y perpendiculaire à la direction x.Using a laser beam, first ferromagnetic bands are then cut out in layer 6, parallel to the x direction. Then a second cutting of the ferromagnetic deposit 6 is carried out, in the direction y perpendicular to the direction x.

Ce laser est un laser à infra-rouge ayant une longueur d'onde de 1060 nm pour un film support 2 en Mylar(R).This laser is an infrared laser having a wavelength of 1060 nm for a support film 2 made of Mylar (R) .

Après la réalisation des traits de gravure 10, on effectue un recuit entre 150 et 300°C, en présence d'un champ magnétique

Figure imgb0001
tournant ou fixe de quelques centaines d'A/m (80 kA/m) contenu dans le plan du film support 2.After the etching lines 10 have been produced, an annealing is carried out between 150 and 300 ° C., in the presence of a magnetic field.
Figure imgb0001
rotation or fixed of a few hundred A / m (80 kA / m) contained in the plane of the support film 2.

Le dépôt ferromagnétique 6a, peut aussi, selon l'invention, être constitué de bandes ferromagnétiques 12 comme représentée sur la figure 2.The ferromagnetic deposit 6a can also, according to the invention, consist of ferromagnetic strips 12 as shown in FIG. 2.

On peut aussi déposer, comme décrit ci-dessus, une seconde couche ferromagnétique 14 sur la face 16, opposée à la face 4, du film support. Cette couche 14 peut être constituée de bandes parallèles 18 ou de pavés. Les traits de gravures 20, 22 (figure 2) des dépôts ferromagnétiques supérieur 6a et inférieur 14 peuvent être décalés.It is also possible to deposit, as described above, a second ferromagnetic layer 14 on the face 16, opposite the face 4, of the support film. This layer 14 can consist of parallel strips 18 or paving stones. The etching lines 20, 22 (FIG. 2) of the upper 6a and lower 14 ferromagnetic deposits can be offset.

Suivant l'application envisagée, on empile et assemble plusieurs structures ou feuilles telles que représentées sur les figures 1 ou 2.Depending on the application envisaged, several structures or sheets are stacked and assembled as shown in FIGS. 1 or 2.

Il est aussi possible, comme représenté sur la figure 3, de déposer des matériaux isolants électriques 24 et 26 sur respectivement les dépôts ferromagnétiques 6 et 14a revêtant les deux faces 4 et 16 du support 2. Sur cette figure, les dépôts 6 et 14a ont la forme de pavés carrés. Il en est de même pour les matériaux isolants 24 et 26. La structure complète porte la référence 25.It is also possible, as shown in FIG. 3, to deposit electrical insulating materials 24 and 26 on the deposits respectively ferromagnetics 6 and 14a coating the two faces 4 and 16 of the support 2. In this figure, the deposits 6 and 14a have the shape of square blocks. The same applies to the insulating materials 24 and 26. The complete structure is marked with the reference 25.

Ces couches isolantes ont une épaisseur de 10 à 100 nm. Leurs traits de gravure sont réalisés en même temps que ceux des dépôts ferromagnétiques, avec un faisceau laser et sont donc en coïncidence.These insulating layers have a thickness of 10 to 100 nm. Their etching lines are produced at the same time as those of the ferromagnetic deposits, with a laser beam and are therefore coincidental.

Sur la figure 4, on a représenté un empilement de plusieurs structures 25, ou feuilles. Le nombre de feuilles 25 peut aller de 50 à 500. L'assemblage de ces feuilles est obtenu à l'aide d'un joint de colle. La colle utilisée est un polyester fluide résistant à la température.In Figure 4, there is shown a stack of several structures 25, or sheets. The number of sheets 25 can range from 50 to 500. The assembly of these sheets is obtained using an adhesive joint. The adhesive used is a fluid polyester resistant to temperature.

L'empilement de ces différentes feuilles peut être réalisé par bobinage, drapage ou toute autre technique connue.The stacking of these different sheets can be carried out by winding, draping or any other known technique.

Par ailleurs, le film de colle est obtenu par pulvérisation, ce qui permet de déposer des épaisseurs de colle largement submicroniques, typiquement de 0,2 micromètre.Furthermore, the adhesive film is obtained by spraying, which makes it possible to deposit thicknesses of adhesive that are largely submicron, typically 0.2 microns.

A titre illustratif, on donne ci-après plusieurs exemples de réalisation de matériaux composites conformes à l'invention.By way of illustration, several examples of embodiment of composite materials in accordance with the invention are given below.

EXEMPLE 1EXAMPLE 1

On effectue par pulvérisation cathodique un dépôt de 400 nm d'épaisseur de Co₇₉Zr₁₀Mo₉Ni₂ sur les deux faces d'un film de Mylar(R) de 3,5 micromètres se déplaçant à 20 cm/min. Ce dépôt est effectué, sous un champ magnétique plan de 800 A/m, dans un bâti BVT de pulvérisation cathodique dans lequel un vide résiduel inférieur à 10⁻⁵ Pa a été effectué.Is carried out by sputtering a 400 nm thick deposit of Co₇₉Zr₁₀Mo₉Ni₂ on both sides of a Mylar (R) film of 3.5 micrometers moving at 20 cm / min. This deposition is carried out, under a plane magnetic field of 800 A / m, in a BVT cathode sputtering frame in which a residual vacuum of less than 10 a Pa has been carried out.

On effectue ensuite un dépôt de SiO₂ de 50 nm d'épaisseur sur chaque dépôt ferromagnétique par PECVD (dépôt chimique en phase vapeur assisté par un plasma).A 50 nm thick deposit of SiO₂ is then carried out on each ferromagnetic deposit by PECVD (chemical vapor deposition assisted by a plasma).

Après un recuit à 230°C, en présence d'un champ magnétique plan de 70 kA/m, de la structure obtenue, on effectue alors à l'aide d'un laser YAG de 1060 nm des traits de gravure de 100 micromètres de large, pour les couches de SiO₂ formées des pavés de 3 mm de côté. Cette gravure est effectuée avec un défilement de la feuille de 0,15 m/s.After annealing at 230 ° C., in the presence of a plane magnetic field of 70 kA / m, of the structure obtained, etching lines of 100 micrometers are then made using a 1060 nm YAG laser. wide, for the SiO₂ layers formed of pavers of 3 mm side. This engraving is carried out with a scrolling of the sheet of 0.15 m / s.

300 feuilles obtenues comme ci-dessus sont assemblées, l'adhésion étant assurée par un film de colle polyester de 0,2 micromètre.300 sheets obtained as above are assembled, adhesion being ensured by a 0.2 micrometer polyester adhesive film.

Le matériau composite obtenu présente une perméabilité magnétique de 90 et une densité de 2, soit un rapport µ/d de 45.The composite material obtained has a magnetic permeability of 90 and a density of 2, ie a µ / d ratio of 45.

EXEMPLE 2EXAMPLE 2

Cet exemple 2 se différencie de l'exemple 1 par l'utilisation de 50 feuilles collées, constituées chacune d'un seul dépôt de Co₈₇Nb11,5Zr1,5 de 400 nm sur le film de Mylar, recouvert d'une couche mince de 20 nm de SiO₂. Les traits de gravure sont les mêmes que dans l'exemple 1.This example 2 differs from example 1 by the use of 50 glued sheets, each consisting of a single deposit of Co₈₇Nb 11.5 Zr 1.5 of 400 nm on the Mylar film, covered with a thin layer of 20 nm of SiO₂. The etching lines are the same as in Example 1.

Ce matériau composite présente une densité de 2 et un rapport µ/d de 7 à 300 MHz.This composite material has a density of 2 and a µ / d ratio of 7 to 300 MHz.

Les variations de la perméabilité magnétique de l'ensemble en fonction de la fréquence de l'onde incidente sont données sur la figure 5 ; les fréquences sont mentionnées en échelle logarithmique.The variations in the magnetic permeability of the assembly as a function of the frequency of the incident wave are given in FIG. 5; frequencies are reported on a logarithmic scale.

EXEMPLE 3EXAMPLE 3

Dans cet exemple, le matériau composite est formé de 50 feuilles collées, constituées chacune d'un dépôt de 400 nm de Co₈₇Nb11,5Zr1,5 sur les deux faces d'un film de Mylar(R) de 3,5 micromètres d 'épaisseur, ce dépôt étant recouvert d'une couche mince de 20 nm de SiO₂. Les traits de gravure sont les mêmes que dans l'exemple 1.In this example, the composite material is formed of 50 glued sheets, each consisting of a 400 nm deposit of Co₈₇Nb 11.5 Zr 1.5 on both sides of a 3.5 micrometers film of Mylar (R) thick, this deposit being covered with a thin layer of 20 nm of SiO₂. The etching lines are the same as in Example 1.

Ce matériau composite présente une densité de 2,5 et un rapport µ/d de 10 à 300 MHz.This composite material has a density of 2.5 and a µ / d ratio of 10 to 300 MHz.

Les variations de la perméabilité de l'ensemble en fonction de la fréquence de l'onde incidente sont données sur la figure 6 ; les fréquences sont illustrées sous forme logarithmique.The variations in the permeability of the assembly as a function of the frequency of the incident wave are given in FIG. 6; frequencies are illustrated in logarithmic form.

Les figures 5 et 6 montrent clairement que la perméabilité magnétique des matériaux composites de l'invention reste stable sur de grands domaines de longueur d'onde.Figures 5 and 6 clearly show that the magnetic permeability of the composite materials of the invention remains stable over large wavelength ranges.

Dans le tableau ci-après, on a indiqué le rapport µ/d des matériaux composites des exemples 1, 2 et 3 pour différentes fréquences d'onde électromagnétique incidente ainsi que celui d'un matériau traditionnel en ferrite.The table below indicates the µ / d ratio of the composite materials of Examples 1, 2 and 3 for different frequencies of incident electromagnetic wave, as well as that of a traditional ferrite material.

Il ressort clairement de ce tableau que les matériaux composites résultant de l'invention présentent un rapport µ/d plus élevé que celui de la ferrite et que ce rapport reste constant même aux fréquences élevées.

Figure imgb0002
It is clear from this table that the composite materials resulting from the invention have a higher µ / d ratio than that of ferrite and that this ratio remains constant even at high frequencies.
Figure imgb0002

Claims (15)

  1. Process for the production of a composite material in the form of sheets (12) having at least 50 to 500 integral sheets, consisting of shaping each sheet by passing a polymer support film (2), which is mechanically and thermally strong and having a thickness below 10 µm, into a deposition enclosure where there is a residual volume of, 10⁻⁵Pa and continuously depositing on at least one of the faces (4, 16) of the moving film a 300nm to 10 µm thick coating (6,6a, 14,14a) of a ferromagnetic amorphous compound and assembling the sheets obtained, the density (d) and the magnetic permeability (µ) of the composite magnetic material being such that 5≦µ/d≦100.
  2. Material according to claim 1, characterized in that the support film (2) is thermally stable between 150 and 300°C.
  3. Material according to claims 1 or 2, characterized in that the support film (2) is a material chosen from among polyimides, polycarbonates, polyesters and ethylene glycol polyterephthalates.
  4. Material according to any one of the claims 1 to 3, characterized in that the support film (2) has a tearing strength of at least 18 kg/mm².
  5. Material according to any one of the claims 1 to 4, characterized in that the ferromagnetic layer has a thickness of 300 to 800 nm.
  6. Material according to any one of the claims 1 to 5, characterized in that the ferromagnetic compound is a cobalt-based compound with a magnetic permeability above 300.
  7. Material according to any one of the claims 1 to 6, characterized in that the ferromagnetic compound is chosen from among Co₈₇Nb11.5Zr1.5 or Co₇₉Zr₁₀Mo₉Ni₂.
  8. Material according to any one of the claims 1 to 8, characterized in that the ferromagnetic layer has etching lines (10, 20, 22) defining parallel strips (18) or blocks (8).
  9. Material according to any one of the claims 1 to 8, characterized in that the ferromagnetic layer is coated with a thin, electrically insulating layer (24, 26)
  10. Process according to claim 9, characterized in that the thin insulating layer (24, 26) has a thickness of 10 to 100 nm.
  11. Production process according to any one of the claims 1 to 10 for a magnetic material, whereof each ferromagnetic layer has etching lines (10, 20, 22), characterized in that the etching lines are produced continuously on each sheet of moving material with the aid of a laser beam.
  12. Process according to any one of the claims 1 to 11, characterized in that a magnetic field is applied parallel to the plane of the support film during the deposition of the ferromagnetic compound of each sheet.
  13. Process according to claim 11 or 12, characterized in that the laser has a wavelength essentially transmitted by the support film (2).
  14. Process according to any one of the claims 1 to 13, characterized in that an annealing takes place under a magnetic field (B) of the composite material.
  15. Process according to any one of the claims 1 to 14, characterized in that the sheets are rendered integral by an adhesive film.
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Publication number Priority date Publication date Assignee Title
FR2698479B1 (en) * 1992-11-25 1994-12-23 Commissariat Energie Atomique Anisotropic microwave composite.
JPH09232141A (en) * 1996-02-28 1997-09-05 Unitika Ltd Magnetic element
DE10114021B4 (en) * 2001-03-22 2005-09-08 Forschungszentrum Karlsruhe Gmbh Thermal radiation device for additional targeted thermal processing of an object in a microwave oven
CN1522449A (en) * 2001-08-31 2004-08-18 Tdk株式会社 Laminated soft magnetic member, soft magnetic sheet and production method for laminated soft magnetic member
US7989095B2 (en) * 2004-12-28 2011-08-02 General Electric Company Magnetic layer with nanodispersoids having a bimodal distribution
EP2561232B1 (en) * 2010-04-19 2015-12-16 Pierburg Pump Technology GmbH Electric motor-vehicle coolant pump
CN108022714B (en) * 2016-10-31 2021-06-08 北京北方华创微电子装备有限公司 Soft magnetic film and preparation method thereof
CN108022751B (en) * 2016-10-31 2022-01-11 北京北方华创微电子装备有限公司 Deposition method of magnetic thin film lamination, magnetic thin film lamination and micro-inductance device
CN107394414B (en) * 2017-07-18 2020-07-31 东南大学 Wave absorber based on double-layer magnetic medium to realize low-frequency bandwidth broadening

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2620853A1 (en) * 1987-09-18 1989-03-24 Commissariat Energie Atomique COMPOSITE MAGNETIC MATERIAL AND METHOD FOR MANUFACTURING THE SAME

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2620853A1 (en) * 1987-09-18 1989-03-24 Commissariat Energie Atomique COMPOSITE MAGNETIC MATERIAL AND METHOD FOR MANUFACTURING THE SAME

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
Journal of the Electromechanical Society, Vol. 136, No. 6, June 1989, The Electromechanical Society Inc., (Manchester, NH, US), O.J. Wimmers et al.: "Taper etching of an amorphous soft magnetic CoNbZr alloy using an interfacial organosilane layer", pages 1769-1772 *

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DE69006368D1 (en) 1994-03-10
FR2655180A1 (en) 1991-05-31
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EP0502940A1 (en) 1992-09-16
DE69006368T2 (en) 1994-08-04
US5328523A (en) 1994-07-12

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