JPS60115011A - Thin film magnetic head - Google Patents

Abstract

PURPOSE:To eliminate recesses and projections of an upper core and to improve the characteristics of a thin film magnetic head, by burying a conduction coil pattern into a substrate with no protrusion over the substrate and setting an insulated layer completely flat. CONSTITUTION:Recess grooves 11 are formed at the expected areas for formation of conduction patterns on a ferromagnetic substrate 10 serving as a lower core. Then the area over a rear part 12 of the lower core is removed to form a nonmagnetic thin film 13, and conduction coil patterns 14 are formed on the film 13 in the groove 11. A flat insulated layer 15 is formed on the conduction coil 14 and the film 13 at the side of a tip part 10' of the substrate 10. Then a ferromagnetic thin film 16 which interlinks over the pattern 14 is formed up to the part on the film 13 of the part 10' from the part 12 via the area over the layer 15. Thus a thin film magnetic head contains a completely flat upper core part 18.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to a technique for forming a conductive coil and an upper core of a thin film magnetic head.

BACKGROUND TECHNOLOGY Recently, high recording density has been required for magnetic recording devices such as DA, T (digital audio tape recorder), but linear recording density is approaching its limit, and this will dramatically increase in the future. Since no improvement can be expected, the idea is to achieve a higher recording density by increasing the overall track density. Therefore, thin-film heads, which can easily achieve high track density, have begun to be used in place of conventional bulk heads. However, the fill forming technology for thin film heads has not yet been established, and has the drawback of causing a decrease in the magnetic flux transmission efficiency of the upper core, which will be described below. That is,
As shown in FIG. 1, a thin film head generally has a non-magnetic thin film 2 formed on a substrate 1 serving as a lower core to form the entire magnetic gap 5, and then the thin film 2 is completely formed on the substrate 1 which becomes the lower core. A conductive coil pattern 3 is wound several times on the conductive fill pattern 2, and a ferromagnetic material serves as an upper core that is directly connected to the substrate 1 other than the thin film 2 and rides on and interlinks with the conductive fill pattern 3 through the entire insulating layer 4. A thin film 5 is provided.

However, when forming one on the ferromagnetic material i@5, the first
As shown in the figure, conductive films 3, 3.・・・・・・
Since the difference in the thickness of the pattern causes a step sound in places where there is and where there is not, the surface of the insulating layer 40 is also uneven in accordance with this. Therefore, is the front part 6 that rides on the conductive coil of the ferromagnetic substrate 5 also uneven? The front portion 6 has four sloped portions 7, 7 . . . ., the magnetic resistance becomes thicker than that of the flat portion, leading to a decrease in magnetic flux transmission efficiency7.

This problem is caused by the fact that even if the magnetic flux passing through the entire rear section 8 is as set, positive W (IK) propagation will not be possible up to the important front gap 9, which will cause the recording/reproducing characteristics of the thin-film head to deteriorate completely. It had become.

DISCLOSURE OF THE INVENTION Purpose of the Invention This invention relates to the above-mentioned irregularities in the upper core. This was proposed with the sole purpose of solving this problem and improving the characteristics of the thin film head.

Structure of the invention □ This invention has the following objectives: 1. In order to achieve this, all of the following configuration means were adopted. In other words, in this invention, a non-magnetic thin film, a conductive fill pattern, and an insulating layer are laminated on a flat ferromagnetic substrate serving as the lower core, and are directly bonded to the ferromagnetic substrate at the rear, and the front Regarding the formation of the upper core which rides on and interlinks with the conductive fill pattern in the part and forms a front gap, that is, a magnetic gap 1f with the ferromagnetic substrate which is the lower core at the tip part, the following structure is adopted. First, in this invention, the conductive coil pattern is
The insulating layer is buried so as not to protrude from the substrate, and the entire insulating layer is set completely flat, thereby forming an upper core having a flat front portion.

Effects of the Invention If this invention is fully implemented, the unevenness in the upper core will be eliminated and the recording and reproducing characteristics of the thin film head will be improved. moreover,
According to this invention, the conductive coil is.

Since the dimensions and shape are set by embedding it in the substrate, it can be designed to match the processing accuracy of the substrate. Also, in this invention,
Since the insulating layer can be easily set to a completely flat shape, it has an excellent advantage that the conductive coil and the upper core can be reliably insulated. The effects of the present invention described above will become clearer from the implementation described below.

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 2 to 6 are cross-sectional views of a thin film magnetic head according to an embodiment of the present invention. When introducing this embodiment in its entirety, for convenience of explanation, the manufacturing process will be shown in Figures 2 to 5. The completed magnetic head is shown in FIG. First, as shown in FIG. 2, the entire Mn-2n single crystal ferrite substrate 10 is prepared, and the entire spiral groove 11 is formed in the area where the conductive coil pattern is to be formed. In this groove 11 formation 1,
Hot phosphoric acid solution? Either wet etching may be used, or all areas other than the intended areas may be masked by resist coating and then dry etching may be performed using ion milling. Next, as shown in Figure 3, on the rear part 12 of the lower core? An insulating and non-magnetic 5i02 film 13i, which also serves as a magnetic gap spacer, is formed on the entire surface including the entire inner surface of the groove 11, except for the above, by reactive sputtering means. Then as shown in Figure 4.

Groove 11 is formed by AJ or Oui sputtering means.
The conductive fill pattern 14 is formed by adhering to the 8102 film 13 on the inner surface. This IIJ11E coil pattern 1
The surface 14/ of 4 must be set to be flush with the flat 5i02WA13. As shown in FIG. 5, i! on the tip 10' side of the substrate 10! Phil 14 and 5
102 SiO on most of the film 13, that is, on the tip 10'
A flat insulating layer 15 is provided on almost the entire surface of the upper core where the front portion is to be formed. In this case, the turbidity of the insulating layer 15 is 5in2 or A71203.
In the case of oxides such as oxides, a reactive sputtering method is used, and in the case of resists and rubbers/resins such as polyimide, a sol-like material is applied. After that, from the rear part 12 of the lower core through the entire top of the insulating layer 15 to the top of S'1021113 of the tip part 10', ? When the upper core 18 consisting of the front part 16 and rear part Nia is completely formed by sputtering or plating the entire ferromagnetic material such as e80 part, Ni2O part alloy or Sendust alloy, the desired thin film magnetic head is formed. is obtained.

The thin film magnetic head described above has a completely flat absolute M layer 1.
Since the front part 16 of the upper core 18 is formed on top of the front part 16 of the upper core 18, the unevenness of the conventional part is eliminated, and the difference in level between the front part 16 and the rear part 17 can also be reduced, which improves the magnetic flux transmission of the upper part 18. Tsuji efficiency is greatly improved. Furthermore, in this thin film magnetic head, the conductive coil 14 has a concave r.
Since the dimensions and shape are determined by being buried in the tlj l l, a precise conductive coil 14 can be created by fully utilizing photolithography technology, which is currently undergoing remarkable technological innovation, and improving the etching accuracy of the concave groove 11. I can make it.

Note that since the insulating layer 15 can be formed in a flat shape, the insulating distance between the conductive coil 14 and the front part 16 of the upper core 18 is as follows.
Needless to say, the thickness of the insulation N15 allows reliable insulation treatment.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view showing the entire conventional general thin-film magnetic 4 head, FIGS. 2 to 5 are cross-sectional views showing each manufacturing process of a thin-film magnetic head according to an embodiment of the present invention, and FIG. FIG. 1 is a sectional view of a thin film magnetic head shown in an embodiment of the present invention. 10... Ferromagnetic substrate (lower core), 11... Groove, 13... Non-magnetic thin film (5i02 film), 14... Conductive coil pattern, 15... Insulating layer, 16. ...Front part, 17...Rear part, 18...Upper core.

Claims (1)

[Claims] On the ferromagnetic substrate that becomes the lower core, there is no non-magnetic thin film for forming a magnetic gap, and all the conductive coil patterns are formed on the non-magnetic thin film, and it is directly bonded to the substrate using other than the non-magnetic thin film. In a device in which the entire ferromagnetic thin film is formed as an upper core that rides on and interlinks with the conductive coil pattern through the insulating layer, the conductive coil pattern is entirely buried in the base plate. A thin-film magnetic head characterized by a completely flat insulating layer.