DE1948375A1 - Method of manufacturing a magnetic head - Google Patents

Description

Sep

MATSUSHIiTA E3JECTRIC IKBIJSTRIAL CO., LTS. Osaka, Japan

Method of manufacturing a magnetic head

Me invention relates to a method of manufacture a magnetic head.

To manufacture a magnetic head with a core made of Permalloy has hitherto been a method in which a thin film of beryllium steel or similar material is used Thickness corresponded to a predetermined gap width between the two Parts of a magnetic core was inserted and held by these. However, this method is used as the material for the magnetic core Ferrite is used, -so no secure connection can be made between the thin film and the ferrite core, and the thin film therefore tends to peel off the core, as does ferrite material is often the case. The magnetic head then only has a very limited service life.

Another method has also become known in which • is evaporated in non-magnetic material such as SiO, so that it is on those surfaces of the core parts of the magnetic head which

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determine the gap to form a layer of predetermined Strength comes with the layer formed in this way as a gap serves. However, if the core is made of ferrite, it is Strength to that formed by a layer of such material Gap is not mooring, and this leads to the operation of the Magnetic head often breaks at the cleavage point.

To eliminate this deficiency, one then went over to a thin glass hielit clay slightly greater in strength than that predetermined gap width between the surfaces defining the gap of the two core parts to then put the glass on his To heat the softening point and with the help of a limit gauge on a

"To compress a predetermined strength, after which the glass is allowed to cool

leaves and so forms the gap. This method is suitable for making a magnetic head with a gap of a few microns. With this method known from the prior art, however, it is difficult to produce a limit gauge for very small gap widths or to bring it into a suitable arrangement if a gap with a thickness iros 1 u © that is less is to be formed, as is the case, for example, with devices for tape recording of television signals is required, and it is difficult to form such a thin film of glass. On the other hand, the glass must be pushed aside against the capillary action, and this is almost impossible. In practice it has therefore proven to be n <51 & .g . * To apply a thin glass layer with a thickness corresponding to a multiple of a predetermined gap width, but this has the consequence that the core parts move against each other when pressed together, which in turn is insufficient Dimensional accuracy of the gap formed is conditional. In addition, the glass material is only heated to its softening point, so that the formation of a semi-rigid connection between the ferrite of the plastic parts and the glass film is not guaranteed.

"Given this, there is one more method

has been developed, which is inserted between the two-.K@ra.teiluchter ..., bistanzstück from vorbestlssatar Stark® so as to see this sEaszusparea free tree, which is then due to the capillary! ~ :. · \ - ^: --Λ.λ . ■. : ■ - .;. ; did

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t; -; t is filled with molten glass. This method "offers the T-Ts.shr for the formation of a sufficiently rigid connection between: - of the glass and the core parts and for a correspondingly durable S- * * eise of the magnetic head thus formed. If, however, a gap width v -; - 1 u or approximately this value is desired, then that is Depth of penetration caused by the capillarity of the gesehaolzenen There are limits to the glass in the gap. The penetration behavior also changes with the type of glass material used, and in particular In this case, filling the rear gap part with glass is problematic. In addition, there is only a very limited number of types of glass to choose from with this method, as the hard © of the glass material compared to that of the core material of the magnetic head must be big enough.

Accordingly, it is an object of the invention to remedy those shortcomings to switch off the arrangements known from the prior art occur, and to provide a method of manufacturing a magnetic head which is also straightforward to implement and is reliable when the gap provided in the magnetic head is only to have a very small width.

Another object of the invention is to provide a method for producing a magnetic head with a required gap width without a thin layer of glass to apply, the thickness of which corresponds essentially to the desired gap width.

Bes further the invention also has an object to To provide a method of making a usable magnetic head, which makes it possible to provide any gap width or gap depth of the magnetic head.

These and other objects and features of the invention result with greater clarity from the context of the following description in conjunction with the accompanying drawings. In point to the drawings

Figures la and Ib top views of the core of the magnetic head β to explain a implementation fona of the invention created procedure!

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Figures 2a and 2b are similar views of the core of the magnetic head to explain another embodiment of the invention Procedure?

Figure 3 is a cross-sectional side view of an embodiment of the atomization system used in the context of the invention?

Figures 4a and 4b are perspective views respectively a top view to explain a further embodiment of the invention! and

Figures 5a and 5b are top views for explanation another embodiment of the invention.

For the description it should now be assumed that a core of a magnetic head made up of two flat, TJ-shaped core parts consists, which are arranged in opposition to one another, as such U-shaped core parts for producing a magnetic head on most commonly used.

According to the bar position of Figure la is a core part 1 with a substantially flat, U-shaped cross-sectional formation in manufactured in such a way that a front surface defining a gap 2 and a rear surface 3, which also defines a gap, are designed as mirror-like, smooth surfaces which are in alignment with one another, line layer 4 consisting of silicon oxide is by vapor deposition or by deposition from a gaseous phase, for example by a sputtering process or the like, onto this front and rear gap-defining surface 2 and 3 applied. If you get lost in vapor deposition the material SiO contained in a Hegel is used for this purpose in vacuum for evaporation for a predetermined period of time to a heated predetermined temperature so that on the front and the rear of the gap-defining surfaces of the core part 1 a SiO-Sehehens of predetermined strength.

Are in the evacuated tree small oxygen levels present, it köffiiat before evaporating to eixmr of SiO in SiOg and on the front and rear surfaces 2 Bezie% UAG * weiae 3 of the core parts 1 toldet twiddles eoiiii '' £ &. "- SiOg layer · ■ &&& *

It has been shown that the crucible is preferably exposed to a temperature of about 1200 ° C. and in a vacuum of the order of magnitude of 10 Torr must bring in order to achieve satisfactory results.

If the atomization method is used, the atomization system shown in FIG. 3 can be used. A core 1 (made of ferrite) of a magnetic head is supported by a substrate holder 11 made of aluminum to which a voltage of -10 V is applied. At a distance of up to 30 mm from the surface of the core 1 to be vaporized, a silicon wafer 12 is arranged, which is carried by a quartz plate 13 (cathode), to which a voltage of -1000 V can be applied. The silicon wafer 12 can have a Bur ohmesse r of 40 mm. The sub-area encompassing the quartz plate 13 must be isolated from the chamber 14, which has been evacuated to a vacuum of 0.1 to 0.2 Torr, and at the same time, if necessary, be water-cooled. Since the substrate holder 11 can be overheated as a result of the sputtering, a thermocouple 15 is provided which is used to monitor the temperature of the holder 11. An anode 16 is arranged below the substrate holder 11, so that the silicon wafer 12 is sputtered in the sighting of the anode 16. A gas inlet valve I7 can serve to let a gas flow in if its presence is required for the evaporation process. _{With this arrangement, an SiO 2} layer can be formed on the core part 1 at a growth rate of 0.2 µ per hour. The timing of the atomization process is therefore freely adjustable.

The core provided with a SiOp layer in this way can be used to manufacture a magnetic head, although it should be noted that in this magnetic head core the strength at the connection point between SiO ₂ and ferrite still leaves something to be desired and it is therefore desirable to subject the magnetic head core to a heat treatment again so that the SiO _{9 is} firmly fused with the ferrite of the core.

However, this method cannot be used in practice, since silicon oxide SiO ₂ (or SiO) normally heats up at around 1400 ° C and the ferrite at this :? Tea temperature under change of his

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Baked magnetic properties further. Also herewith is a significant limitation in the number of jigs for the jig available materials connected.

To lower the melting point of the silicon oxide, an additional layer is therefore provided within the scope of the invention, for example a layer 5 consisting of PbO, for example, _{which is applied to the layer 4 of silicon oxide SiO 2} (or SLO), for example by vapor deposition or sputtering as shown in Figure Ib. In this case it is considered to convert the SiO into SLOp beforehand by adding this
Is subjected to heat treatment.

To convert SLOp by placing it in an oxygen atmosphere

Banaeh becomes the core part 1 bucket heat treatment at a Temperature in d @ ai range from 500 to 800 C subjected to what the Melting point τοπ. Lead glass corresponds so that it becomes an implementation comes between SLOp and PbO with the formation of lead glass, which then the between the SiO «layer and the ferrite core part 1 Fills in gaps. Bas lead glass that fills the spaces remains continued to stand up, so that at the ierri tobe rf pool a chemical Binding takes place and the Spaltstell® is mechanically significant is reinforced.

If one of a gap having a width of 1 utilizes the formation and a lead glass, the zn 40 "weight percent of SiO ₉ and 60 weight percent? Besteilt b0, then this procedure in practice 'so that SiO ₂ as ScMssiit with a strength of

0.73 u is applied and PbO as a layer with a thickness of 0.27 u. Ferrite core part 1, on which these two layers are formed, is brought into opposition to another ferrite core part 6 on which no other layer is formed, and then these two core parts are subjected to a heat treatment at a temperature of 500 to 600 ° C, whereby the two layers are transformed into a mass of completely pressure-melted lead glass, so that a gap made of glass with a thickness of 1 u is obtained.

The PbO layer can easily be placed on the ferrite core part 1 be shaped by the fact that in the above-mentioned atomization

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system instead of silicon to work with lead, or that one in sinaia PbO contained in the crucible is heated for evaporation in a vacuum by means of a heating device Ms.

You can also use a low oxygen content © ii in one Work low vacuum in such a way that the lead oxidizes when it evaporates is and is in the form of PbO on dsm ferrite core 1 precipitates.

Another Altemativmögliöhksit "consists darisi that mesa, the lead in the metal phase au a layer having a thickness of 0.21 u to the SiO _- layer aufdampf5 xuiC thereto, the lead layer in an oxidizing atmosphere & vt about 300 C heated that way. to form a PbO layer with a thickness of 0.27 u, which is then further heated to 500 to 600 ° C, whereby the two layers of SiOp and PbO with a total thickness of 1 ρ fuse together to form a uniform mass of lead glass.

If, on the other hand, it is desired to fill the gap with a glass mass consisting of 20 percent by weight of SiOp, 20 percent by weight of ZnO and 60 percent by weight of PbO, with a gap width of 1 ρ, then SiO _? , Zn and PbO are applied as layers with a thickness of 0.47 p> 0.19 ρ and 0.34 U, respectively, and these layers are then subjected to a heat treatment at a temperature close to 600 ° C, whereby it is possible to form a glass mass from this existing gap.

The procedure will now be described when it is intended that the SiOg-Sohioht chemically through a conversion from the gas phase on the core part of the magnetic head to form it.

The gas used is a silane gas such as for example SiH-, SiCl. or similar. Bern Silane gas becomes oxygen gas or water vapor is added and this mixture is introduced into a furnace heated to about 200 to about 50 ° C., so that the silicon-containing gas is thermally split with the formation of SiOg will.

Once the ferrite core has been placed in the furnace, the SiO ₂ produced is deposited on the surface.

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In one embodiment of the invention, an argon gas flow of 100 cm / min, in which SiH ^ in one Percentage of 1000 parts per million is included, with an oxygen stream of 20 cm / min and with a nitrogen flow of Mix 1 liter / min and heat this mixture to 350 ° C. A ferrite core part is placed in the heated mixture on which As a result, a SiOp layer develops with a growth rate of 200 i / min. Instead of heating the mixture it can also be provided that one is responsible for the production of SiOg operated by a high-frequency electric field.

In the embodiments described above, the layers made of SiO _? , PbO and SaO formed only on one of two core parts. As is now shown in FIG. 2a, the layer 4 made of silicon oxide can also be applied to one of the two core parts 1 and 6 and the layer 5 made of PbO can be applied to the other of these core parts. If desired, however, the layers of SiO 2 and PbO can also be provided on each of the two core parts with a thickness of 0.56 u and 0.14 u, as can also be seen from the illustration in FIG. 2b. is. In the latter case, the PbO layer can be located below the SiOp layer.

It is of course also possible to have these layers only on the front and rear gap-defining surface of the two core parts or, if necessary, only on the front surface defining the gap "" before each core part to be provided by making a corresponding Cover with a mask. Bies is an effective method if a coil is to be wound directly onto the core, because some deposit materials have a relatively low Resistance, which could short-circuit the turns of the coil if the coil insulation is damaged.

Although the description in the above focused on the case that a _{lead glass composed of SiO 2} and PbO or a glass composed of SiO ₃ , ZnO and PbO is formed, other glass materials are also possible here, for example a phosphorus silicate glass, consisting of GeO ₂ and PbO or a borosilicate glass, which was made up of SiO ₂ and B ₃ O ₂ together.

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Referring now to Figure 4a, there is illustrated yet another embodiment of the invention. In this case, a core part is provided with a length m, which amounts to a multiple to more than ten times the required gap depth. The front gap-defining surface 2 of this core part is formed with an exposed part, the width 1 of which is greater than a predetermined gap width. On the remaining parts of the front gap-determining surface 2 layers 7 made of a material such as titanium or chromium are applied by vapor deposition in a thickness corresponding to a predetermined gap width t, which is relatively difficult to implement with such a glass, but which is at a relatively high temperature in finely divided state can be evaporated. SiO and PbO, for example, are then vapor-deposited onto the exposed part of the front gap-defining surface 2. This core part is pressed in the manner described above against another core part, as shown in FIG a width corresponding to the thickness t of the layers 7. In this case the thicknesses of the SiO2 and PbO layers do not have to correspond exactly to the required gap width Core part, which is to be _{vapor-deposited with SiO 2} and PbO, as well as changes can be made with regard to the order in which these materials are vapor-deposited and the above description of the arrangement is accordingly not to be interpreted in a restrictive sense.

After the gap has been formed, the core arrangement is divided into lengths corresponding to the required gap depth and the layers J are then removed from each individual core in the manner indicated in FIG. 4b by a broken line.

Another embodiment of the invention is shown in Figure 5a shown. Two core parts 1 and 6, on which a glass-forming mass is provided, are arranged in opposition to one another and are pressed against each other. A glass-forming mass 8, whose Melting point equal to that of the glaze-forming mass of layers 4 and

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is applied to the core assembly at two locations near the front and rear of the gap-defining surfaces. The core arrangement is subjected to a heat treatment at a temperature of 500 to 800 ⁰ C, so that the layers 4 ~ ® && 5 of the glass-forming mass provided in the gap part are vitrified and completely melted, so that a gap 9 consisting of glass is created, like this is shown in Figure 5b.

The glass-forming material 8 is also melted and forms glass tubes 10, which form the two core parts 1 and 6 near the front and rear of the gap-defining surfaces, connect them to each other in a bridging manner.

Pintuck glass layers 10 are intended to improve the mechanical To increase the strength of the magnetic head, and in the material of this Layers 10 can be any non-magnetic binder which, due to its composition, is suitable for reinforcement purposes is suitable, for example around glass or enamel. Has the material used for the layers 10 has a higher melting point as the glass-sealing material provided for the magnetic head gap, so it must be at the same time as the glazing of the glass-forming surfaces arranged between the gap-defining surfaces of the two core parts Mass to be melted. In contrast, the melting point of the material used for the layers 10 is lower than that of the glass provided for the cleavage point, it can be done at the same time be melted with this or it can be after vitrification of the Gap-forming layers are applied to the two core parts to be firmly connected to each other.

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Claims (12)

- 11 claims 1. A method for producing a magnetic head, characterized by the process steps of applying a glass-forming mass of predetermined composition to the Spalthe tuning surface (2, 3) of at least one of two at least the gap part of the magnetic head determining core parts (l, 6) with the formation of Layers (4 »5) each with a thickness corresponding to the volume proportion of the respective component of the glass-forming mass on the gap-defining surface (2, 3), the joining of the two core parts (l, 6) and the carrying out of a heat treatment of the joined core parts (l 6) at a temperature close to the melting point of the glass of the composition in question to vitrify the components of the glass-forming mass and to fill the gap between the gap-defining surfaces {2% 3) with a glass of predetermined composition to form a magnet tkop f sp al ts. 2. A method for manufacturing a magnetic head according to claim 1, characterized characterized in that the components of the glass-forming mass by deposition from the gas phase on the gap tbe determining surface (2, 3) are applied. 3 · A method of manufacturing a magnetic head according to claim 1, characterized in characterized in that see the glass-forming mass of FbO and composed. 4. A method of manufacturing a magnetic head according to claim 1, characterized in characterized in that the glass-forming mass is composed of PbO and ZnO. 5. A method for producing a magnetic head according to claim 2, characterized in that for applying SiO_ as a component of the glass-forming mass by deposition from the gas phase SiO is evaporated at negative pressure in an oxygen-containing atmosphere, this being applied to the gap-defining surface (2, 3) one of the core parts (1, 6) is converted into SiO ₂ . 6. A method for producing a magnetic head according to claim 2, characterized in that to apply SiO ₂ as a component of the glass-forming mass by deposition from the gas phase, a mixture 0 0 9 8 U / 1 6 9 5 '^ ; ; Λ - 12 - ■ of SÜangAs and oxygen gas is _{thermally split with the production of SiO 3} , which is reflected in the core of the Magnötkopf which is brought into the gas mixture. 7. A method for manufacturing a magnetic head according to claim 1, characterized characterized in that with a gap width that is not greater is than 5 yes, the total thickness of the area determined by the gap (2, 3) applied layers (4 »5) of the components of the glass-forming Mass is equal to a predetermined width of the gap. 8. A method for manufacturing a magnetic head according to claim 1, characterized in that in the caused by the heat treatment Vitrification of the components of the glass-forming mass a glass-forming material (8) on the surfaces that determine the gap (2, 3) adjacent parts, the core parts (1, 6) is applied and this glass-forming material (8) softens during the heat treatment is and here the two core parts (1, 6) bridging with each other connects. . 9 · A method of manufacturing »a magnetic head according to claim 1, characterized in characterized in that after the formation of a predetermined gap a glass-forming material (8) is applied near the gap and is softened, thereby bridging the two core parts (1, 6) with one another connects. 10. A method for manufacturing a magnetic head according to claim 1, characterized characterized in that the two core parts (l, 6) have a length which is sufficiently larger than a predetermined gap length, and after forming the gap in lengths corresponding to the predetermined gap length are divisible. 11. A method for manufacturing a magnetic head, characterized by the process steps of applying a glass-forming mass of predetermined composition to the gap-determining. Surface (2, 3) at least one of two core parts (1, 6) defining at least the gap part of the magnetic head by deposition from the gas phase Forming of layers (4, 5) each with a corresponding thickness the volume fraction of the relevant component of the glass-forming Mass on the gap-defining surface (2, 3), the application of a Difficult to move material to the gap-defining material with glass area 0098 U / 1JP5 .1848378 Surface (2, 3) of the other of the core parts (1, 6) by deposition the gas phase with the formation of a layer (7) which determines the gap width Layer with a thickness corresponding to the predetermined gap width on the gap-determining surface (2, 3) of the other of the Core parts (1, 6), of the subsequent joining ^ of the two Core parts (1, 6), the undertaking of a heat treatment of the assembled Core parts (1, 6) at a temperature close to the melting point of the glass of the composition in question for vitrifying the components the glass-forming mass and to fill the gap with the glazed components of the glass-forming mass in the form of a glass of predetermined composition, the distance between the two Gap-defining surfaces (2 $ 3) to form a magnetic head gap clearly defined by the layer (7) which determines the gap width is, and the cooling and removal of the gap width determining Layer (7). 12. A method for manufacturing a magnetic head, characterized by the process steps of applying a component of a glass-forming Mass of a predetermined composition on the gap-defining surface (2, 3) -des one of two at least the gap part of the Magnetic head determining core parts (l, 6) by deposition from the Gas phase with the formation of a layer (4) with a thickness accordingly the volume fraction of the component concerned, the application the other component of the glass-forming mass on the one that determines the gap Surface (2, 3) of the other of the core parts (1, 6) also through Deposition from the gas phase with the formation of a layer (5) with a strength corresponding to the volume proportion of this other component, the subsequent joining of the two core parts (l, 6) and performing a heat treatment on the assembled core parts (l, 6) at a temperature close to the melting point of the glass of the subject Composition for vitrifying the components of the glass-forming mass and filling the gap between the two gap-defining compounds Gap areas (2 »3) with a glass of a predetermined composition to form a magnetic head. 0098 14/169 5