JPS6045921A - Production of thin film magnetic head - Google Patents

Abstract

PURPOSE:To prevent generation of a defective step owing to shrinkage of an insulating layer by forming a conductive coil pattern by prescribed stages via an org. resin and protective resist on a nonconductive thin film for forming a magnetic gap. CONSTITUTION:A nonmagnetic (SiO2) thin film 11 is deposited on a ferrite base plate 10 over the part for forming a conductive coil 17 from one end thereof and an org. polymer resin 12 is coated only on the part for forming said coil 17 thereon. Protective resist 13 is coated thereon over the entire part and is subjected to a baking treatment. A metallic (masking) film 14 is deposited thereon by evaporation. Photoresist 15 is formed in the region except the part intended for forming the conductive coil pattern thereon and the part of a window 16 is chemically etched away. The window 16 is then dug out by reactive dry etching and the conductive coil material is sputtered over the entire area. The resist 13 is removed by a solvent to form the conductive coil pattern 17. The generation of a defective step owing to shrinkage of an insulating layer 11 is thus prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a coil forming wave Iho 1 of a thin film magnetic head.

Background Art Recently, magnetic recording devices such as A and T (digital audio tape recorders) are required to have high recording densities, but the linear recording density is approaching its limit, and it is expected that this will be dramatically increased in the future. Since no improvement can be expected, it has been considered to achieve higher recording density by increasing the track density. Therefore, conventional bulk
Thin film heads, which can easily achieve high trunk densities, have begun to be used instead of conventional heads. However, the coil forming technology for thin film heads has not yet been established, and has the drawback of causing magnetic flux disturbance in the upper core, which will be described below. Two non-magnetic thin films for forming a magnetic gap are formed on the substrate 1, and a conductive coil pattern 3 is wound several times on the thin film 2, and the conductive coil pattern 3 is directly bonded to the substrate 1 with something other than the thin film 2. In addition, a ferromagnetic thin film 5 serving as an upper core is provided which rides on and interlinks with the conductive coil pattern 8 via the insulating layer 4. In this case, the upper surface of the insulating layer 4 is uneven depending on the presence or absence of the conductive coil pattern 3.

Then, when forming the ferromagnetic thin film 5, the uneven step boundaries 6.6. The problem was that the magnetic flux was concentrated at the stepped portions 5', 5', 7, and the magnetic flux leaked to the lower core1.

The reason why magnetic flux concentration occurs at the stepped portions 5', 5', ... is that the material of the insulating layer 4 undergoes considerable volumetric contraction, causing abnormal roughness in the vicinity of the stepped portions 5', 5', etc. The problem lies in forming a surface. Moreover, recently, insulating layer 4
When a polyimide resin or the like, which has good heat resistance and is capable of blocking the intrusion of radiation from the outside and preventing erroneous recording, is used, the above-mentioned drawbacks are even more noticeable.

DISCLOSURE OF THE INVENTION This invention has been proposed as a result of studies in consideration of the above technical background.
The purpose of this method is to enable immediate formation of a conductive coil in an insulating layer, and to eliminate defective steps caused by shrinkage. That is,
Regarding the formation of a conductive coil and an insulating layer, the present invention is designed to form a coil pattern 11 in advance for forming a magnetic gap.
An organic polymer resin and a protective resist are applied to the entire surface of the non-magnetic thin film containing f1s, and the outside of the area W where a conductive coil pattern is to be formed is masked with a metal film using photolithography technology to form a conductive coil pattern. After removing only the organic polymer resin on the planned area, a conductive coil material is applied to the entire surface, and the conductive material, metal coating, and protective resist are removed from the area other than the area where the conductive coil pattern is planned to be formed using a lift-off method. This method employs a method in which a conductive coil pattern is flatly embedded in an organic polymer resin. Therefore, according to the present invention, by forming the uppermost insulating layer after flat embedding, it is possible not only to eliminate the defective step difference, but also to significantly reduce the number of man-hours required for manufacturing thin films. There is.

BEST MODE FOR CARRYING OUT THE INVENTION When carrying out this invention, there are the following embodiments.
Its best form can be easily recalled.

FIGS. 2 to 11 are cross-sectional views at various steps of manufacturing a thin film according to an embodiment of the present invention.

First, as shown in FIG. 2, a Mn-2, single crystal ferrite substrate 10 is prepared, and from one end of the substrate slo, which is a non-magnetic material, is connected to the conductive coil forming portion.

A membrane 11 is applied. Next, as shown in Figure 8,! 9i
0. Only on the conductive coil forming part on the membrane 11, an insulating material and heat resistant polyimide resin such as DuPont's PI-
2555 resin 12 is applied to the entire surface, cured at about 450°C, and then a protective resist 18 is applied which is soluble in solvents such as acetone, positive type, and has good adhesion to fully flexed materials.
is applied and baked at 80°C to 150°C.

Next, using a vapor deposition method, several thousand amps of Ti is deposited on the protective resist 18 as shown in FIG.
form. Thereafter, as shown in FIG. 5, for the purpose of applying photolithographic technology, an ultraviolet-sensitive cyclized rubber photoresist 15 is fixed on the masking film 14 corresponding to the area other than the area where the conductive coil pattern is to be formed. ,
Photoresin l-1 of the masking film 14 as shown in FIG.
5. The exposed portion of the window 16 that is not fixed is removed by chemical processing or ching. Then window +<l
! The protective resist 18 and polyimide 1-' resin 12 corresponding to No. 16 were subjected to gas plasma etching, that is, reactive dry etching, in an oxygen atmosphere.
As shown in FIG. 7, the window 16 is dug down and removed. At this time, on the window 16, the masking film 14 is applied to the protective resin 1-12.
The polyimide resin 12 protrudes into the window from the periphery of the window due to an undercut phenomenon that occurs during the etching process, forming an eave. Therefore, as shown in FIG. 8, A1! which is the conductive coil material 17! M is applied over the entire area by the spattering method. In this case, since the masking film 14 is in the eaves state as described above, the M17 is covered only from the 5ift film 11 at the bottom to part of the polyimide resin 12 and protective resist 13 at the side wall in the angular part 16. I'm not wearing it. Thereafter, when immersed in a solvent such as acetone, the protective resist 18 swells and dissolves, so that the protective resist 12 and masking film 14 and the overlying Al! 17
only is removed as shown in FIG. That is, at this point, the conductive coil material AC17 is formed flat and embedded in the polyimide resin 12. After the above processing steps, photosensitive polyimide resin 12' is coated and developed as a two-layer insulating layer on the flat buried surface 18 as shown in FIG. The two-part core 19 is formed by depositing the agglomerate nucleator to form the desired thin film.

According to the above-mentioned thin film/nod manufacturing method, not only the problems caused by the unevenness of the insulating layer, which conventionally existed, can be solved, but also
As shown below, it can also contribute to reducing the number of man-hours required for processing thin films. That is, when a polyimide resin or the like is used as the insulating layer material, the above 1. Since these tend to contract during curing and form unevenness on the surface, it is necessary to correct the protrusions by etching several times. However, in this embodiment, the insulating layer is embedded in the conductive coil in one lift-off operation, and only the unnecessary deposited portions need to be etched at that time, so the process can be performed only once, reducing the number of man-hours.

[Brief explanation of drawings]

FIG. 1 is a cross-sectional view showing the lfi ratio of a general thin-film magnetic head, and FIGS. 2 to 11 are cross-sectional views of the thin film in each manufacturing process showing an embodiment of the present invention. . 10: Substrate (lower core), 11-: Non-magnetic thin film, 12.12': Organic polymer resin, 13: Protective resist, 14: Metal coating (masking film) ,
17... Conductive coil pattern, 1B-...
...Flat buried surface, 19... -Ferromagnetic thin film (upper core). m]o figure 1] figure

Claims (2)

[Claims] (1) A non-magnetic thin film for forming a magnetic gap is formed on a ferromagnetic substrate that will become the lower core, a conductive coil pattern is provided on the non-magnetic thin film, and a non-magnetic thin film is formed on the non-magnetic thin film. In a method of forming a ferromagnetic thin film which becomes an upper core which is directly bonded to a substrate and which rides on and interlinks with a conductive coil pattern through a layer, a coil pattern is formed in advance with respect to the conductive coil and the insulating layer. Spread organic polymer resin and protective resist for a total of 1 m on the non-magnetic thin film including the planned area, and use photolithography to mask the outside of the area where the conductive coil pattern is planned to be formed with a metal coating to form the conductive coil pattern. Remove only the organic polymer resin on the part by etching. After that, the conductive coil material is applied to the entire surface, and the conductive material, metal coating, and protective resist outside the area where the conductive coil pattern is to be formed are peeled off using lift 1-off, and the conductive coil pattern is flatly embedded in the organic polymer resin. A method for producing a thin film magnetic helix, characterized by forming a thin film magnetic helix. (2) A method for manufacturing a thin-film magnetic head, characterized in that the organic polymer resin according to claim 1 is a polyimide resin.