JPS6292213A - Magnetic head - Google Patents

Abstract

PURPOSE:To intensify the recording magnetic field, enable high-density recording and carry out precise information recording by differentiating the film thicknesses of the lower magnetic layer and the upper magnetic layer in accordance with the distance from the leading end. CONSTITUTION:The film thickness of the leading end of the lower magnetic layer 1 of the magnetic head is regulated to t1 and the thickness of the part from a position l1 from the leading end to the terminal end is controlled to t2. The film thickness of the leading end part of the upper magnetic layer 2 is adjusted to t3 and the thickness of the part from a position l2 from the leading end to the terminal end is regulated to t4. A coil 3 consisting of a conductor layer and an interlayer insulating layer 4 for insulating the magnetic layer 1 from the magnetic layer 2 are formed between the magnetic layers 1 and 2. The film thicknesses t1 and t2 of the leading end parts of the respective magnetic films 1 and 2 are optimally determined in accordance with the recording wavelength. The film thicknesses t3 and t4 as described above are made as thick as possible in the range where the constraint conditions of the process are satisfied, thereby reducing the magnetoresistance of the magnetic head.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to the structure of a magnetic head.

[Summary of the invention]

In the structure of a magnetic head, the present invention changes the thickness of each magnetic layer of the lower magnetic layer and the upper magnetic layer between the tip portion of the magnetic layer and the other portions, and adjusts the thickness to an appropriate value at the position where the thickness changes. From what I decided to do, I went to magnetism with high write efficiency and playback efficiency;
can get.

[Prior art]

Conventional magnetic head structures have a structure in which both the bottom magnetic layer and the top magnetic layer are composed of one layer each, and the thickness of the magnetic layer is uniform, or the thickness of the magnetic layer is thinner near the tip. Similarly, in order to lower the magnetic resistance, the thickness is increased except near the tip, or the bottom magnetic layer and the top magnetic layer are multi-layered, and the junction between the bottom magnetic layer and the top magnetic layer is formed in the process. For the purpose of alleviating the step difference between magnetic layers, a layered structure was created in which the layers were stacked so that only the tip of the magnetic layer was thinner, as described above.

[Problems and objects to be solved by the invention] However, in the above-mentioned prior art, if the upper and lower magnetic layers are uniform,
In precise high-density recording where the thickness of the magnetic layer is determined by the recording wavelength, the thickness becomes thinner and the magnetic resistance becomes higher. In addition, with a single magnetic layer, the tip is thin only at the near end, or a multi-layer laminated one, where the tip is thin only at the near end <L7t.Only the tip for recording and reproduction is thin, and the other parts are thick. h: The above problem is solved without becoming large. However, if the distance to the point where the thickness changes (l) is too large, the magnetic flux will not reach the thick part of the magnetic layer during recording and playback, but will leak around.On the other hand, if it is too close to the tip, For example, during recording, when the magnetic flux goes around from the lower magnetic layer to the upper magnetic layer (in other words, from the upper magnetic layer to the lower magnetic layer) and the magnetic flux from the gap decreases, this causes nine problems. This invention solves these problems, and its purpose is to provide a highly efficient magnetic helidic structure by determining the optimum distance from the tip of the magnetic layer to the point where the thickness changes. K
be.

[Elaborate means to solve problems]

Regarding the magnetism of the present invention, in a thin film magnetic head in which the thickness of the upper and lower magnetic layers is uneven, the distance from the tip of the magnetic layer to the part where the thickness of the lower magnetic layer changes is tx the thickness of the upper magnetic layer. When the distance to the changing part is 12, it is assumed that the following constituent requirements ζ... are satisfied.

α) 4 μm≦t1≦15 μm b) 1 μm≦t2≦j Ottm [Function] According to the above structure of the present invention, the thickness of the magnetic layer tip and the portion other than the tip is reduced and the dimensional range is determined. Due to the following, the magnetic resistance is small, the magnetic field is small, and the magnetic field strength near the gap during writing is the optimum value 1! It is obtained.

〔Example〕

FIG. 1 is a cross-sectional view of a magnetic head according to an embodiment of the present invention.
The thickness of the tip of the lower magnetic layer 1 is t! and the distance from the tip is 7
The film thickness after + is configured to be t2. Similarly, the lower magnetic layer 2 has a thickness of t3 at the tip and a thickness of t4 at a distance of 12 and beyond from the tip. The nine parts sandwiched between the lower magnetic layer 1 and the upper magnetic layer 2 consist of a coil 3 made of a conductor layer and an interlayer I# skin to insulate the coil and the upper and lower magnetic layers, forming a magnetic node. are doing.

Thickness tl of the tip of the lower magnetic layer 1 and thickness t of the upper magnetic layer 2
3 has an optimum value determined by the recording wavelength5.
゜It is desirable to increase the film thickness is, i+ of the portion other than the tip of the magnetic layer as thick as the process constraints allow in order to reduce the magnetic resistance at the magnetic node. Figure 2 shows the magnetic flux density generated from the gap portion 5 at time t when the distance 6 where the film thickness of the lower magnetic layer 1 changes from tl to h and the distance 7111i72 where the film thickness of the lower magnetic layer 2 changes from mu to mu. It is a diagram showing
The following curve is obtained by changing the lower magnetic field Nj1+ by 7 digits, and 8
This is a curve obtained when the upper magnetic layer 12 is changed. 2+
It is strongest when it is between 4μm and 15μm. tl
If the distance becomes smaller, leakage occurs between the upper magnetic layer 1 and the spacer density bz of the gap portion 5' decreases. If 1+ becomes smaller, the rising angle 6 of the upper magnetic layer shown in FIG. 1 becomes larger, making it difficult to form the upper magnetic layer.

On the other hand, if tl becomes too large, the magnetic flux density from the gap portion decreases, so it is preferably 15 μm or less, more preferably 13 μm or less h. The relationship between the distance t2 of the upper magnetic layer and the magnetic flux density is that from 1 μm to 6 μm, the amount of change in magnetic flux density is small6
The decrease in t "total h" - becomes large at 10 μm or more, and decreases to nearly half at 10 μm or more, so tz
The range h is preferably from 1 μm to 10 μm; particularly preferably from 1 μm to 6 μm.

〔Effect of the invention〕

As described above, according to the present invention, the thickness of the lower magnetic layer and the upper magnetic layer can be adjusted within the respective distance ranges from the tip. By determining the non-uniform film thickness, a strong recording boundary is generated, a high recording density is possible, and accurate information recording b'- can be provided at low cost.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a sectional view showing the magnetic head of the present invention. FIG. 2 is a graph showing the distance between magnetic layers and the generated magnetic flux density. 1...Lower magnetic layer 2...Top magnetic layer 3...Coil 4...Interlayer insulating layer 5...Gap portion 6... ...Rising angle 7...Lower magnetism/? ! Change in 1+ and generated magnetic flux density 8...Change in upper magnetic layer 12 and generated magnetic flux density or more

Claims (1)

[Claims] In a thin-film magnetic head in which the thickness of the upper and lower magnetic layers is non-uniform, the distance from the tip of the magnetic layer to the portion where the thickness of the lower magnetic layer changes is l_1, and the portion where the thickness of the upper magnetic layer changes is defined as l_1. A magnetic head characterized by having the following configuration requirements, where the distance to the top is l_2: a) 4 μm≦l_1≦15 μm b) 1 μm≦l_2≦10 μm