JPS62217415A - Manufacture of thin film magnetic head - Google Patents

Abstract

PURPOSE:To simplify a film forming process, and to form a thick film by flattening the upper face of an insulating and protecting film by using a multi stage bias sputtering method. CONSTITUTION:On a substrate 10, the ferromagnetic thin film 11 of a sendust alloy, etc., which becomes the lower core is formed, on which the thin film 12 of Al2O3, etc., for forming a magnetic gap is accumulated, and on the film 12, a spiral conductor coil pattern 13 is formed. Subsequently, by a multistage bias sputtering method, the flattened insulating and protecting film 14 of SiO2, etc., is formed thinly. Next, on the film 14, the ferromagnetic material thin film which becomes the upper core is formed. According to this method, the film 14 whose surface is flat can be formed by a concise process, and also, a sufficiently thick film is obtained, and the upper core is also formed easily.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application of Industry-1- This invention relates to a method for manufacturing a magnetic non-magnetic head for R/W of magnetic recording devices such as DAT (Deftal Audio Tape Recorder) and computers. The present invention relates to a technique for flattening the insulation protective coating of the conductor pattern.

Background of the Invention Recently, magnetic recording devices that perform PCM (pulse code modulation) recording, including DAT, require processing of the amount of information between strips in order to digitize analog signals, and are more efficient than conventional magnetic recording devices. There is also a demand for even higher recording densities. In the case of DAT and the like, the linear recording density of magnetic tape is approaching its limit, and it cannot be expected that it will be dramatically improved in the future. Therefore, in DAT etc.
Thin-film heads, which can easily achieve high track density, are beginning to be used in place of conventional bulkheads. However, the magnetic head has the drawback that the conductive coil forming technology thereof has not yet been established, and that it causes magnetic flux disturbance in the L portion core, which will be described below. That is, as shown in FIG. 3, a thin film head generally has a non-magnetic thin film 2 formed on a substrate 1'2 which becomes the core of the L portion, and then forms a non-magnetic thin film 2' on the thin film 2' to form a magnetic gap. A conductive fill pattern 3 that is wound several times, and a conductive coil pattern 3 that is directly connected to the substrate 1 other than the thin film 2 and that rides on the conductive coil pattern 3 through the insulating layer 4 to become a super high two-part core. A ferromagnetic thin film 5 is provided. In this case, the upper surface of the insulating layer 4 is uneven depending on the presence or absence of the conductive fill pattern 3. Then, when forming the ferromagnetic thin film 5, the step boundaries 6, 6 . Step portions 5", 5',
The problem was that the magnetic flux was disturbed and leaked to the lower core.

Problems to be Solved by the Invention As described above, the step portion 5 Z51. The reason why the magnetic flux is undesirably disturbed in .

Moreover, in order to perform PCM recording, this thin-film head is configured into a multi-head configuration consisting of several dozen heads shown in Figure 3, so it is necessary to take heat generation into consideration, and the current flowing through one head is reduced. Instead, there is a tendency to increase the number of turns of the conductive coil. Therefore, the throat to the thin film is
Eliminating the level difference in the insulating layer 4 in the conductive coil is extremely important. At present, the following methods are available as a countermeasure for eliminating the above-mentioned step difference in the throat of the thin film. First, the first method is introduced in the Institute of Electronics and Communication Engineers technical research report MR&(]-35. At the time when the conductive coil pattern 3 is formed, the substrate 1
is placed on a spinner, polyimide resin is applied to the insulating parts of the conductive coil pattern, and a flattened organic film is formed by spin coding. However, in this case, there is a limit to the operating temperature, and during subsequent adhesion of the protective glass plate or annealing of the ferromagnetic thin film 5, there is a risk that the solvent will fly off and the protective film will be defective. Next, part 2
As shown in IEICE technical research report MR8θ-24, after forming the conductor coil pattern 3, a photoresist is attached only to the conductor coil pattern 3-1-, and the edges of the photoresist are thermally Reduce sag 5
A so-called lift-off method is used in which a 102 film is deposited on the pattern gap and the photoresist-H by vapor deposition, and the 5102 film on the second pattern is removed together with the photoresist. In this case, a complicated step called a lift-off method must be performed, which is disadvantageous in terms of manufacturing man-hours and cost. And number 3 is Sharp Technical Report 1982
As introduced in the June issue 2G, S10 is pre-coated on the conductor coil pattern 3 using plasma CVD method.
A thin film is formed in advance, and the SIO film is formed. By the way, in this case, there is a drawback that the sputtering adhesion stress at the time of forming the ferromagnetic thin film 5 causes distortion, which may cause cracks in Sl02M, and the insulation protection is impaired.

Means for Solving the Problems This invention was proposed after considering the above-mentioned circumstances.When a conductor coil pattern is provided on a substrate serving as a lower core and a thin insulating protective coating is formed, In this method, multi-stage bias sputtering is performed on the uneven portions of the insulating protective film, and the convex portions on the J portion are removed by sputter etching and flattened. In other words, this invention eliminates the disadvantages of micro-cracks occurring on the convex side and collapse of the conductor coil pattern shoulders when simply performing bias sputtering, and also promotes the advantage of obtaining a sufficiently thick insulating protective film. It is something.

Effects According to this invention, Parts 1 to 3 introduced as prior art
As is clear from the comparison with the above method, it does not require the use of an organic film, it is easy to form a sufficiently thin film even at high temperatures, the thin film forming process is simple, and it is possible to form a sufficiently thick film. Moreover, in this invention, as will be seen from the examples described later, the sputter etching removal of the upper surface of the insulating protective film can be controlled by multi-stage bias voltage, so there is no need to unnecessarily increase the film thickness of the insulating protective film immediately before multi-stage bias sputtering. disappears.

-〇- Embodiment Fig. 1 is a sectional view of an inductive thin film head, which is an intermediate material, obtained by carrying out an embodiment of the present invention. An alloy thin film 11 was deposited to a thickness of several μm, and then an AQ203 thin film I2, which also served as a magnetic gap spacer and coil-lower core insulating layer, was deposited at several thousand amps.
About 11 tm of Cu was deposited, and a spiral Cu conductor pattern 13 of 1 to several μm, which would become a coil, was formed using the two-stage bias sputtering method described below.
A flattened insulating protective coating 14 of 510 □ is formed as a thin film.

Now, in order to form the insulating protective coating 14 of 5102, first, as shown in FIG. 2, an RF magnetron sputtering device is used as before, and an RF power of 500 W is used.

Bias voltage - 100V1 Vacuum exhaust pressure 7 X IO'Pa
, 4 to 5 under conditions of Ar (inert) gas pressure of 0 and 1 Pa.
By performing time sputtering, the step difference caused by the presence of the conductor pattern 13 is reduced to several micrometers (here, even by conventional bias sputtering, the step difference hl of the insulating protective film 14 can be reduced to a few μm). Although it is possible to make the sputtering smaller than that, it is not possible to obtain perfect flatness.The principle of bias sputtering is well known, but it can be explained as follows. , the Ar gas is ionized and incident on the 5102 target L (4"φ) in the sputtering device, where it is physically etched and deposited over an area including the conductor pattern I3 and the loose 203 thin film 12. However, Ar ions are also incident on the - band, and the convex portion 15 is etched again, albeit somewhat roughly, so that the height difference ht can be set to less than the height difference.

Next, RF power 500W, bias voltage -350■,
Vacuum exhaust pressure 7 X IO'Pa, Ar gas pressure 0.1Pa
By carrying out the second stage sputtering for 3 to 4 hours under these conditions, the inductive thin film head of the intermediate workpiece shown in FIG. 1 is obtained. In this case, the step height h2 of the insulating protective film 14 can be made several micrometers smaller than that of the first (first stage) bias sputtering, which improves the flatness accuracy by about ten times. Successful.

In the above embodiment, the high frequency to ionize the inert gas was an RF wave, but the present invention is not limited to this, and if necessary, it may be used as a micro wave, and the bias voltage setting is not necessarily two-stage. However, it may be 3 or more steps.

Effects of the Invention According to the present invention, it is not necessary to use an organic film, a coated film, or a lift-off method to form an insulating protective film on a conductor coil pattern, and the thickness of the insulating protective film can be set and controlled as desired. Therefore, it becomes easier to form a part of the core that is formed later, and there is an effect that improved mass productivity and improved reliability can be achieved at the same time.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view of an inductive thin film magnetic head, which is an intermediate product obtained as a result of an embodiment of the present invention, and FIG. FIG. 3 is a sectional view of a conventional thin film magnetic head. DESCRIPTION OF SYMBOLS 10...Substrate, 11...Ferromagnetic film (lower core), 12...Nonmagnetic thin film, 13...Conductor coil pattern, 14...Insulating protective film.

Claims (1)

[Claims] A non-magnetic thin film for forming a magnetic gap is formed on a ferromagnetic substrate serving as a lower core, a conductive coil pattern is provided on the non-magnetic thin film, and a conductive coil pattern is further provided on the conductive coil pattern. A method of forming a thin insulating protective coating, and further forming a ferromagnetic thin film that is directly bonded to the substrate with something other than a non-magnetic thin film, and which becomes an upper core that rides on and interlinks with the conductor coil pattern via the insulating protective coating. A method for manufacturing a thin film magnetic head, comprising: after forming the insulation protective film, the upper surface of the insulation protective film is flattened by a multi-stage bias sputtering method.