JPH01264619A - Thin-film magnetic head - Google Patents

Abstract

PURPOSE:To improve head efficiency by forming a gap for writing and magnetic paths together with an excitation coil on a nonmagnetic substrate and disposing the magnetic paths flatly without superposing the same. CONSTITUTION:The thin-film magnetic head is formed by forming a lower magnetic pole 2, an insulating layer 3, the plane coil 4, an insulating layer 5, and an upper magnetic pole 6 respectively to prescribed shapes on the nonmagnetic substrate 1. The magnetic pole 6 and magnetic pole 2 of this magnetic head are connected in the outside circumferential part. The magnetic pole 6 and the coil 4 in contact with the magnetic pole 6 are in contact with each other respectively via the layer 3 and the layer 5. The magnetic pole 6 and the magnetic pole 2 are superposed on each other on the plane. The magnetic resistance between both is thereby increased much larger than the magnetic resistance of the main magnetic paths. The magnetic leakage between both is, therefore, decreased and the magnetic efficiency is improved.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a magnetic head used for magnetic recording and magnetic printing devices, and relates to a planar magnetic head formed on a non-magnetic substrate. It's about.

[Prior Art] Conventional magnetic heads generally include bulk heads made by machining and thin film heads made by a thin film manufacturing process. Bulk heads and thin film heads each have their own characteristics, and are widely used as elements of magnetic recording devices.

Magnetic printing apparatuses have various characteristics and have various advantages, such as the image quality they produce, speed, multicolor property, and stability of image quality with respect to the environment.

However, electrostatic type products have become mainstream in the field of page printers, including copying machines. This is simply because the head that handles writing could not be made at a low price and of good quality. □ For heating, head technology used in magnetic recording devices is often applied directly to magnetic printing devices, and bulk heads with coils wound around ferrite or metal magnetic materials are often used.

On the other hand, if you try to print quickly with a small number of heads, the cost of the heads will not be an issue and you can just move the magnetic recording medium at high speed. Needless to say, in this case, a high-speed response of the head is required.

On the other hand, write heads using thin film head technology, which is beginning to be used in magnetic recording devices, have also been proposed. Thin film heads can be easily multi-layered in one direction.

[Problems to be Solved by the Invention] When a large number of bulk heads are used, the cost increases almost in proportion to the number of heads, so it is difficult to create multiple heads or lines. In the example described in Jikai No. 57-73745, as many as 3,380 individual heads are arranged.

In order to configure a magnetic printing apparatus with a small number of heads, the magnetic recording medium must be moved at high speed, and the heads must also be moved at high speed, resulting in a large-scale system. Patent registration number 1251698 is an example of this.

Problems begin to arise when producing a large number of thin-film heads of stable quality, and large-sized ones such as line heads become extremely difficult to produce due to the manufacturing equipment involved. Examples of these include Jikai 60-119615.

The thin film head can be formed with high density, and its shape is
A major feature is that it is flat. However, since the thin film head has a structure in which the upper and lower magnetic poles sandwich the coil, the distance between the upper and lower magnetic poles is very close. For this reason, a large amount of magnetic flux leaks through the coil portion, resulting in a decrease in the efficiency of the head. Furthermore, in order to separate the magnetic poles as much as possible vertically, it is necessary to thicken the insulating layer of the coil, resulting in large steps during the manufacturing process, which poses manufacturing difficulties. It has become.

Furthermore, general thin film heads are processed using G1 machining in order to form the gap depth. For this reason, tolerances on the order of microns are required, which poses a manufacturing bottleneck.

[Means for Solving the Problems] In order to solve the above problems, the present invention forms a writing gap and a magnetic path made of a ferromagnetic material together with an excitation coil on a non-magnetic substrate, and the magnetic path is Arrange them horizontally without overlapping. By arranging them without overlapping, unnecessary leakage of magnetic flux is eliminated and head efficiency is improved. A schematic perspective view of the present invention is shown in FIG. FIG. 2 shows a cross section of the thin film magnetic head of the present invention.

Upper and lower magnetic poles are arranged to surround a planar coil formed in a spiral shape on a non-magnetic substrate, but the magnetic field generated by the coil exits from one magnetic pole to the outside of the coil.
The structure is such that it flows into the opposite magnetic pole. That is,
Isometrically, it is easier to understand if you consider that the coil is tilted 90 degrees, as shown in Figure 3.

The head according to the present invention has the following characteristics because the upper magnetic pole and the lower magnetic pole do not overlap in a plane.

That is, unlike a general thin film head, leakage between the upper and lower magnetic poles is extremely reduced, improving head efficiency. Another issue in the manufacturing process is to connect the parts where there are differences in level, but in this case, the difference in level is reduced by one, making manufacturing easier.

Furthermore, the head according to the present invention can efficiently utilize the magnetic field generated by the coil by locating the write gap in the center of the coil.

Further, as mentioned above, in order to realize a high-speed magnetic printing device, a multi-head or a line head with stable quality is necessary, and the present invention makes it possible to realize this.

In a magnetic printing apparatus having a multi-head or a line head, the speed can be increased by increasing the number of channels, so there is no need to extremely increase the relative speed between the magnetic recording medium and the recording head. Therefore, reliability can be maintained even when the recording head and the magnetic recording medium are brought into contact with each other, and the magnetic printing apparatus can be configured with a simple structure.

[Example 1] The present invention will be specifically described below based on Examples.

FIG. 1 is a schematic perspective view of this embodiment. On a non-magnetic alumina substrate 1, a lower magnetic pole 2, an insulating layer 3, a plane = I-il 4,
The insulating layer 5 and the upper magnetic pole 6 are each formed into a predetermined shape to constitute a thin film magnetic head.

FIG. 2 shows a cross section of the thin film magnetic head of this embodiment. '' The two magnetic poles 6 and the lower magnetic pole 1 are connected at the outer periphery. -1-
, the planar coil 4 which is in contact with the magnetic pole 6 and the lower magnetic pole 1 are in contact with each other via an insulating layer 3 and an insulating layer 5, respectively.

Each thin film is formed by a normal thin film process and patterned into a predetermined shape.

The key point of the present invention is that the upper magnetic pole 6 and the lower magnetic pole 1 do not overlap on a plane, and the magnetic resistance between them is much larger than that of the main magnetic path. There is considerably less magnetic leakage.

[Example 2] Almost the same +f/i as Example 1 using polyimide as a substrate
A magnetic head for a magnetic printing device was fabricated by forming a magnetic head in the form of an array. The size of one head unit is approximately 1
mm, and the bit is 1.5 mm.

By arranging the heads in multiple rows d, it is possible to increase the density.

[Effects of the Invention] As described above, according to the present invention, a high-performance multi-head used in a magnetic recording device can be easily formed.

The magnetic path is outside the coil part! 11, crosstalk that adversely affects adjacent heads is reduced when multi-heads are used, which is advantageous when increasing density.

Furthermore, since a high-performance multi-head can be easily formed, a high-speed magnetic printing device can be realized.

Although the present invention has been described with the write gap located at the center of the coil, most of the effects of the present invention remain the same even if the write gap is located outside the coil.

[Brief explanation of the drawing]

FIG. 1 shows a schematic perspective view of a magnetic write head of the present invention. FIG. 2 shows a cross section of the magnetic write head of the present invention. FIG. 3 is a conceptual diagram in which the coil is rotated 90 degrees in order to understand the magnetic write head of the present invention. FIG. 4 is a cross-sectional view of a general thin film head used in hard disk drives. ] Non-magnetic substrate 2 Lower magnetic pole 3 Insulating layer 4 Planar coil 5 Insulating layer 6 Upper magnetic pole 7 Protective layer and above Applicant Seiko Epson Corporation

Claims (3)

[Claims] (1) In a planar head formed on a non-magnetic substrate, it has a write gap and a magnetic path made of ferromagnetic material together with an excitation coil, and the write gap is at the center of the spiral planar coil. 1. A thin film magnetic head, characterized in that excitation paths are arranged in a plane without overlapping each other. (2) Magnetic printing, which has a magnetic recording medium with a magnetizable spreading surface and a head capable of writing a magnetic latent image onto the magnetic recording medium, forms the magnetic latent image on the magnetic recording medium, and then visualizes it with magnetic toner. 2. The thin film magnetic head according to item 1, which is used in an apparatus. (3) The thin film magnetic head according to item 2, wherein the nonmagnetic substrate is made of a flexible material and is in contact with the magnetic recording medium when forming the magnetic latent image on the magnetic recording medium.