CA1047161A - Magnetic head using a magnetic-field-sensitive element and method of manufacturing same - Google Patents
Magnetic head using a magnetic-field-sensitive element and method of manufacturing sameInfo
- Publication number
- CA1047161A CA1047161A CA227,485A CA227485A CA1047161A CA 1047161 A CA1047161 A CA 1047161A CA 227485 A CA227485 A CA 227485A CA 1047161 A CA1047161 A CA 1047161A
- Authority
- CA
- Canada
- Prior art keywords
- groove
- substrate
- magnetic field
- magnetic
- layer
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/39—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects
- G11B5/3903—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using magneto-resistive devices or effects using magnetic thin film layers or their effects, the films being part of integrated structures
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/33—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only
- G11B5/332—Structure or manufacture of flux-sensitive heads, i.e. for reproduction only; Combination of such heads with means for recording or erasing only using thin films
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3109—Details
- G11B5/3116—Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3163—Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic layers
Landscapes
- Engineering & Computer Science (AREA)
- Manufacturing & Machinery (AREA)
- Magnetic Heads (AREA)
Abstract
ABSTRACT OF THE INVENTION
A magnetic head for use in a magnetic reproduction device and comprising a substrate in which a groove is provided. Provided on one wall of said groove is a magnetic field-sensitive element which should be used in a position normal to a recording medium to be coupled to the magnetic head.
A magnetic head for use in a magnetic reproduction device and comprising a substrate in which a groove is provided. Provided on one wall of said groove is a magnetic field-sensitive element which should be used in a position normal to a recording medium to be coupled to the magnetic head.
Description
~47~6~L
"Magnetic head using a magne-tic field-sensitive element and method of manufacturing same".
The invention relates generally to a magnetic head for use in a magnetic reproductlon device. The magnetic head comprises in particular a substrate on which a magnetic field-sensitive element is provided in the form of a thin film, the necessary leads being present to provide electric con-nections to external circuits.
In the manufacture of magnetic heads of the annular core type which so far has been the most usual type, the front face of the head is ground away, while the height of the gap is measured optically so as to de-termine the quantity of the material of the head which has still to be ground away or removed. The more time-consuming and hence expensive character makes such a method unfit for use in the series production of magnetic heads comprising magnetic field-sensitive elements, for example, Hall elements or magnetoresistance elements, in the form of thin films.
In the prior art series production process for heads of the above-described type, a number of magnetic field-sensitive elements in the form of thin films are provided, for example, by vapour deposition in vacuo, on sub-strates of a uniform size which form part of the ultimate head construction;
electric leads for the elements are formed on each substrate by vapour depos-iting a metal thereon; by adhering the substrates each on a glass plate with the side having a thin film, the fundamental construction of a head is ef-fected. When the method conventionally used in manufacturing heads of the annular core type were used, the front face of the head, that is to say the surface which is destined to be coupled to a magnetic recording medium, must then be ground away until a desired uniform height of the magnetic field-sensitive elements has been achieved. Due to the very small dimensions of the elements, the grinding away down to the required height is a very accur-ate and time-consuming job, while in the case of larger numbers of elements on a substrate it is very difficult to ma~e the height of the elements ~147~L6~
uniform. Consequently, heads manufactured in this manner often have un-equal characteristics relative to each other, that is to say, the reprod-ucibility factor of the known method of manufacturing large numbers of uni-form heads of the present type is low.
It is the object of the invention to provide a new and improved magnetic head, as well as a method of manufacturing came, which eliminates the drawbacks of the prior art. The invention provides in particular a head construction in which the grinding away of the front face of the head is no longer necessary.
For that purpose, the magnetic head according to the invention is characterized in that the magnetic field-sensitive element is provided on a side wall of a groove extending in a surface of the substrate.
The invention also relates to a method of manufacturing 1 magnetic head having a magnetic field-sensitive element. Said method is characterized in that a groove having a defined shape is provided in a surface of a sub-strate, that an auxiliary layer is vapour-deposited at a first angle with the substrate on the surface of the substrate on either side of the groove and on a wall of the groove, that a layer of magnetic field-sensitive material is vapour-deposited at a second angle with the substrate on the auxiliary layer on either side of the groove and on the wall of the groove present opposite to the said wall, that the auxiliary layer with the magnetic field-sensitive material present thereon is etched away, and that the remaining layer of mag-netic field-sensitive material is connected to electric leads.
The invention will be described in greater detail, by way of example, with reference to the drawing.
Fig. 1 is a perspective view of a first embodiment of a substrate for a magnetic head according to the invention.
Figs. 2, 3 and 4 are cross-sectional views taken on the line A-B
of the substrate shown in Fig. 1 during three successive stages of the method according to the invention.
Fig. 5 is a plan view of a second embodiment of a substrate for a magnetic head according to the invention.
In Fig. 1, a groove 2 having a readily defined shape is provided in a substrate 1. When a detrition-resistant substrate is required, sapphire or a carbide may be chosen for that purpose and sputter etching is a suitable method of providing the groove 2. If on the contrary silicon is used as a substrate, a groove whose walls extend normal to the surface can be manufactur-ed by means of anisotropic etching. Said normal position is to be preferred because the magnetic field-sensitive element to be provided will in that case also be normal to the surface.
In Fig. 2, an auxiliary layer 3 having a thickness between 500 and lo,ooo R of, for example, Al or Cu is vapour-deposited on the surface of the substrate 1 and on the wall 5 of the groove 2 at an angle ~ with the substrate 1. Due to the shadow effect of sald vapour deposition method, an auxiliary layer is produced only in the places denoted in the Figure.
In Fig. 3 a layer 4 having a thickness of 1000 R of a magnetic field-sensitive material, for example, a material having magnetoresistive properties (like Ni-Fe~, is vapour-deposited on the wall 6 o~ the groove 2 at an angle ~ with the substrate surface.
In Fig. ~, the auxiliary layer 3 with the part of the layer ~ pre-sent thereon is etched away, the layer 4 being broken off at the area of the surface so that only the part of the layer ~ on the wall 6 remains. The height _ hereof is dependent only on the vapour deposition angle and on the place of the edge 7 and can be adjusted accurately. Dimensions of h of, for example, 5 microns t 0.5 can be reali~ed in this manner. Grinding away of the substrate so as to adjust the height is hence not necessary in the method according to the invention.
As has been already stated above, the material of the auxiliary layer 3 may be, for example, Al or Gu. Generally, said layer should consist of a material which can be e-tched away in the presence of a layer ~ which 7~
may not be attacked. In the case in which the layer 4 consists of NiFe, Al is a very suitable material for the auxiliary layer 3.
In Fig. 5, a groove 8 in the form of an open loop has been etched in the substrate 9. In the above-described manner, a layer of magnetoresis-tive material is provided on the outer wall 11 at least in the part of the groove 8 on the right-hand side of the line G-H, via vapour-deposition at a first angle of an auxiliary layer, vapour-deposition at a second angle of a layer of magnetoresistive material, and etching away the auxiliary layer in-cluding the layer of magnetoresistive material present thereon. A layer of lacquer 10 (shaded area) is then provided which covers the part of the groove between C and D which corresponds to the groove 2 in Fig. 1. The remaining part of the groove 8 is then filled up to the surface of the substrate with a conductive mater:ial, for example Au. Due to the oblique transition of the groove at C and D, said conductive material readily contacts the magnetoresis-tive material present on the wall 11. At the points E and F the conductive material can be connected to an external circuit by means of "beam leads"
or a "through hole plating" technique.
If desired it is also possible to fill the groove between C and D
with, for example, SiO for further p-rotection of the magnetoresistive layer provided on the wall 11 thereof. An extra step for building the magneto-resistive element in, as is necessary in the prior art, is not necessary in this case.
"Magnetic head using a magne-tic field-sensitive element and method of manufacturing same".
The invention relates generally to a magnetic head for use in a magnetic reproductlon device. The magnetic head comprises in particular a substrate on which a magnetic field-sensitive element is provided in the form of a thin film, the necessary leads being present to provide electric con-nections to external circuits.
In the manufacture of magnetic heads of the annular core type which so far has been the most usual type, the front face of the head is ground away, while the height of the gap is measured optically so as to de-termine the quantity of the material of the head which has still to be ground away or removed. The more time-consuming and hence expensive character makes such a method unfit for use in the series production of magnetic heads comprising magnetic field-sensitive elements, for example, Hall elements or magnetoresistance elements, in the form of thin films.
In the prior art series production process for heads of the above-described type, a number of magnetic field-sensitive elements in the form of thin films are provided, for example, by vapour deposition in vacuo, on sub-strates of a uniform size which form part of the ultimate head construction;
electric leads for the elements are formed on each substrate by vapour depos-iting a metal thereon; by adhering the substrates each on a glass plate with the side having a thin film, the fundamental construction of a head is ef-fected. When the method conventionally used in manufacturing heads of the annular core type were used, the front face of the head, that is to say the surface which is destined to be coupled to a magnetic recording medium, must then be ground away until a desired uniform height of the magnetic field-sensitive elements has been achieved. Due to the very small dimensions of the elements, the grinding away down to the required height is a very accur-ate and time-consuming job, while in the case of larger numbers of elements on a substrate it is very difficult to ma~e the height of the elements ~147~L6~
uniform. Consequently, heads manufactured in this manner often have un-equal characteristics relative to each other, that is to say, the reprod-ucibility factor of the known method of manufacturing large numbers of uni-form heads of the present type is low.
It is the object of the invention to provide a new and improved magnetic head, as well as a method of manufacturing came, which eliminates the drawbacks of the prior art. The invention provides in particular a head construction in which the grinding away of the front face of the head is no longer necessary.
For that purpose, the magnetic head according to the invention is characterized in that the magnetic field-sensitive element is provided on a side wall of a groove extending in a surface of the substrate.
The invention also relates to a method of manufacturing 1 magnetic head having a magnetic field-sensitive element. Said method is characterized in that a groove having a defined shape is provided in a surface of a sub-strate, that an auxiliary layer is vapour-deposited at a first angle with the substrate on the surface of the substrate on either side of the groove and on a wall of the groove, that a layer of magnetic field-sensitive material is vapour-deposited at a second angle with the substrate on the auxiliary layer on either side of the groove and on the wall of the groove present opposite to the said wall, that the auxiliary layer with the magnetic field-sensitive material present thereon is etched away, and that the remaining layer of mag-netic field-sensitive material is connected to electric leads.
The invention will be described in greater detail, by way of example, with reference to the drawing.
Fig. 1 is a perspective view of a first embodiment of a substrate for a magnetic head according to the invention.
Figs. 2, 3 and 4 are cross-sectional views taken on the line A-B
of the substrate shown in Fig. 1 during three successive stages of the method according to the invention.
Fig. 5 is a plan view of a second embodiment of a substrate for a magnetic head according to the invention.
In Fig. 1, a groove 2 having a readily defined shape is provided in a substrate 1. When a detrition-resistant substrate is required, sapphire or a carbide may be chosen for that purpose and sputter etching is a suitable method of providing the groove 2. If on the contrary silicon is used as a substrate, a groove whose walls extend normal to the surface can be manufactur-ed by means of anisotropic etching. Said normal position is to be preferred because the magnetic field-sensitive element to be provided will in that case also be normal to the surface.
In Fig. 2, an auxiliary layer 3 having a thickness between 500 and lo,ooo R of, for example, Al or Cu is vapour-deposited on the surface of the substrate 1 and on the wall 5 of the groove 2 at an angle ~ with the substrate 1. Due to the shadow effect of sald vapour deposition method, an auxiliary layer is produced only in the places denoted in the Figure.
In Fig. 3 a layer 4 having a thickness of 1000 R of a magnetic field-sensitive material, for example, a material having magnetoresistive properties (like Ni-Fe~, is vapour-deposited on the wall 6 o~ the groove 2 at an angle ~ with the substrate surface.
In Fig. ~, the auxiliary layer 3 with the part of the layer ~ pre-sent thereon is etched away, the layer 4 being broken off at the area of the surface so that only the part of the layer ~ on the wall 6 remains. The height _ hereof is dependent only on the vapour deposition angle and on the place of the edge 7 and can be adjusted accurately. Dimensions of h of, for example, 5 microns t 0.5 can be reali~ed in this manner. Grinding away of the substrate so as to adjust the height is hence not necessary in the method according to the invention.
As has been already stated above, the material of the auxiliary layer 3 may be, for example, Al or Gu. Generally, said layer should consist of a material which can be e-tched away in the presence of a layer ~ which 7~
may not be attacked. In the case in which the layer 4 consists of NiFe, Al is a very suitable material for the auxiliary layer 3.
In Fig. 5, a groove 8 in the form of an open loop has been etched in the substrate 9. In the above-described manner, a layer of magnetoresis-tive material is provided on the outer wall 11 at least in the part of the groove 8 on the right-hand side of the line G-H, via vapour-deposition at a first angle of an auxiliary layer, vapour-deposition at a second angle of a layer of magnetoresistive material, and etching away the auxiliary layer in-cluding the layer of magnetoresistive material present thereon. A layer of lacquer 10 (shaded area) is then provided which covers the part of the groove between C and D which corresponds to the groove 2 in Fig. 1. The remaining part of the groove 8 is then filled up to the surface of the substrate with a conductive mater:ial, for example Au. Due to the oblique transition of the groove at C and D, said conductive material readily contacts the magnetoresis-tive material present on the wall 11. At the points E and F the conductive material can be connected to an external circuit by means of "beam leads"
or a "through hole plating" technique.
If desired it is also possible to fill the groove between C and D
with, for example, SiO for further p-rotection of the magnetoresistive layer provided on the wall 11 thereof. An extra step for building the magneto-resistive element in, as is necessary in the prior art, is not necessary in this case.
Claims (5)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A magnetic head for use in a magnetic reproduction device and comprising a substrate on which a magnetic field-sensitive element is provided in the form of a thin film, leads being present to provide electric connec-tions to external circuitry, characterized in that the magnetic field-sensitive element is provided on a side wall of a groove extending in a sur-face of the substrate,
2. A magnetic head as claimed in Claim 1, characterized in that the magnetic field-sensitive element is a magnetoresistive element.
3. A method of manufacturing the magnetic head as claimed in Claim 1, characterized in that a groove having a defined shape is provided in a surface of a substrate, that an auxiliary layer is vapour-deposited at a first angle with the substrate on the surface of the substrate on either side of the groove and on a wall of the groove, that a layer of magnetic field-sensitive material is vapour-deposited at a second angle with the substrate on the auxiliary layer on either side of the groove 1 and on the wall of the groove present opposite to the said wall, that the auxiliary layer with the magnetic field-sensitive material present thereon is etched away, and that the remain-ing layer of magnetic field-sensitive material is connected to electric leads.
4. A method as claimed in Claim 3, characterized in that the material for the auxiliary layer is Al or Cu and the magnetic field-sensitive material is Ni-Fe.
5. A method as claimed in Claim 3, characterized in that the groove is in the form of an open loop, that the auxiliary layer and the magnetic field-sensitive layer are deposited at least at the area of the central part of the loop and the auxiliary layer is etched away, and that the remaining part of the groove is filled up to the surface of the substrate with a conductive material to form leads which are electrically connected to the magnetic field-sensitive material.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NL7406962A NL7406962A (en) | 1974-05-24 | 1974-05-24 | MAGNETIC HEAD USING A MAGNETIC FIELD SENSITIVE ELEMENT AND METHOD FOR MANUFACTURING THE SAME. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1047161A true CA1047161A (en) | 1979-01-23 |
Family
ID=19821421
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA227,485A Expired CA1047161A (en) | 1974-05-24 | 1975-05-21 | Magnetic head using a magnetic-field-sensitive element and method of manufacturing same |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS51319A (en) |
| BE (1) | BE829374A (en) |
| CA (1) | CA1047161A (en) |
| DE (1) | DE2522861C3 (en) |
| FR (1) | FR2272460B1 (en) |
| GB (1) | GB1497575A (en) |
| IT (1) | IT1038346B (en) |
| NL (1) | NL7406962A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB2003647B (en) * | 1977-09-02 | 1982-05-06 | Magnex Corp | Thin film magnetic recording heads |
| DE3204184A1 (en) * | 1982-02-06 | 1983-08-11 | Robert Bosch Gmbh, 7000 Stuttgart | THICK LAYER MULTIPLE TRACK MAGNET HEAD HIGH TRACK DENSITY |
| NL8201846A (en) * | 1982-05-06 | 1983-12-01 | Philips Nv | SENSOR WITH A MAGNETIC FIELD SENSITIVE ELEMENT AND METHOD FOR MANUFACTURING THAT. |
| JPH0626008B2 (en) * | 1984-11-16 | 1994-04-06 | 三洋電機株式会社 | Magnetoresistive magnetic head |
| EP0185289B1 (en) * | 1984-12-21 | 1988-07-27 | Siemens Aktiengesellschaft | Thin-film magnetic head on a non-magnetic substrate for perpendicular magnetization |
| FR2671220B1 (en) * | 1990-12-27 | 1995-02-17 | Thomson Csf | PROCESS FOR MANUFACTURING MAGNETO-RESISTIVE SENSORS, AND MAGNETIC DEVICE PRODUCED BY SUCH A PROCESS. |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5229607B2 (en) * | 1972-01-01 | 1977-08-03 |
-
1974
- 1974-05-24 NL NL7406962A patent/NL7406962A/en unknown
-
1975
- 1975-05-21 GB GB2180175A patent/GB1497575A/en not_active Expired
- 1975-05-21 JP JP5980075A patent/JPS51319A/en active Pending
- 1975-05-21 CA CA227,485A patent/CA1047161A/en not_active Expired
- 1975-05-21 IT IT2360275A patent/IT1038346B/en active
- 1975-05-22 BE BE156609A patent/BE829374A/en unknown
- 1975-05-23 DE DE19752522861 patent/DE2522861C3/en not_active Expired
- 1975-05-23 FR FR7516123A patent/FR2272460B1/fr not_active Expired
Also Published As
| Publication number | Publication date |
|---|---|
| JPS51319A (en) | 1976-01-06 |
| IT1038346B (en) | 1979-11-20 |
| BE829374A (en) | 1975-11-24 |
| DE2522861C3 (en) | 1978-12-21 |
| DE2522861A1 (en) | 1975-12-04 |
| FR2272460B1 (en) | 1978-09-01 |
| NL7406962A (en) | 1975-11-26 |
| DE2522861B2 (en) | 1978-04-27 |
| FR2272460A1 (en) | 1975-12-19 |
| GB1497575A (en) | 1978-01-12 |
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