JPH0223505A - Magnetic head - Google Patents

Abstract

PURPOSE:To improve the adhering strength among a ferrite core, 'Sendust(R) film, and bonding glass so that the reliability of a magnetic head can be improved by making the interior part of the gap facing surface of the ferrite core rough and forming the 'Sendust(R) film in a state where the film is adhered to the rough surface. CONSTITUTION:In a magnetic head in which a gap 3 is formed by combining two ferrite cores 1 and 2, the interior part of the gap facing surface of the ferrite core 1 is made rough by etching and a 'Sendust(R) film 4 is formed over the section from the roughened surface part 1a to the mirror surface section 1b of the gap facing end face of the core 1. Bonding glass 6 is also adhered to the roughened surface part 1a of the core 1. The adhering strength of the roughened part 1a is much higher than that of the mirror surface section 1b and occurrence of such inferior products that the joining surfaces of the core 1 and film 4 are separated from each other can be reduced sharply.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a magnetic head used in hard disk drives, floppy disk drives, etc., and particularly relates to a metal-in-gap magnetic head in which a sendust film with a high saturation magnetic flux density is interposed in the gap. This invention relates to improvements in the magnetic head of the formula.

(Prior Art) FIG. 2 shows a typical structure of the gap portion of a conventional metal-in-gap type magnetic head. The gap 3 is formed by combining the two ferrite cores 1 and 2.
A sendust film 4 having a high saturation magnetic flux density is formed on the gap-opposing surface of one ferrite core 1 by sputtering or the like (and a gap spacer 5 made of high melting point glass or the like is further formed on the sendust film 4). .

This ferrite core 1 and the other ferrite 2 are combined, and this part is bonded with a bonding glass 6 made of low melting point glass.

(Problems to be Solved by the Invention) In order to form the gap 3 with high precision, the surfaces of the ferrite cores 1 and 2 facing the gap are mirror-finished with high precision. The sender dust Wj 44 and the bonding glass 6 are attached to the mirror-finished portion of the ferrite core 1, so the adhesion strength is not very high. During the manufacturing process until the magnetic head is finally completed, various forces act between the two ferrite cores 1 and 2, including a force that separates the two cores 1 and 2 from the gap 3. At this time, since the adhesion strength between the mirror surface portion of the ferrite core 1, the gap spacer 5, and the bonding glass 6 is not very strong, these mating surfaces tend to peel off relatively easily, which is a major cause of a decrease in yield.

This invention was made in view of the above-mentioned conventional problems, and its purpose is to increase the adhesion strength between the ferrite core, sendust film, and bonding glass, and to mass-produce reliable and high-precision magnetic heads with high yield. It's about doing.

(Means for Solving the Problems) Therefore, in the present invention, the back part of the gap facing surface of the ferrite core to which the sendust film is attached is roughened, and the sendust film is also applied to this roughened part. It is now possible to form adhesion.

(Function) Since the roughened portion of the ferrite core is located at the back of the gap, it does not affect the accuracy of the gap at all. Since the sendust film is also formed on the roughened portion of the core, the adhesion strength on the roughened portion is much greater than the adhesion strength on the mirror surface portion, making it difficult for this mating surface to peel off.

(Embodiment) FIG. 1 shows the structure of a gap portion of a magnetic head according to an embodiment of the present invention. Basically, it is the same as the one in Figure 2, and the gap 3 is formed by combining two ferrite cores 1 and 2, but the saturation magnetic flux density is reduced by sputtering on the surface of the straight rod-shaped ferrite core 1 facing the gap. A high sendust film 4 is formed, and a gap spacer 5 of a predetermined thickness made of stabilized zirconia or alumina is further formed on the sendust film 4 by sputtering or the like. This ferrite core 1 and the other ferrite core 2 are combined, and this part is bonded with bonding glass 6 made of low melting point glass.

The characteristic feature of the present invention is that the deep part of the gap-opposing surface of the ferrite core 1 is roughened by etching, and the sendust film 4 is formed from this roughened part 1a to both the mirror-finished part 1b on the tip side of the gap. The point is that The bonding glass 6 is also attached to the roughened portion 1a of the ferrite core 1.

(Effects of the Invention) As explained in detail above, in the case of the magnetic head according to the present invention, the sendust film interposed in the gap portion is attached to the roughened portion of the ferrite core at the back of the gap. The adhesion strength between the film and the ferrite core is sufficiently greater than in the past, and the incidence of defective products that peel off from this mating surface is greatly reduced. Therefore, high-performance, highly reliable metal-in-gap magnetic heads can be mass-produced with high yield.

[Brief explanation of the drawing]

FIG. 1 is an enlarged view of a gap portion of a magnetic head according to an embodiment of the present invention, and FIG. 2 is an enlarged view of a gap portion of a conventional magnetic head. 1... Ferrite core 2... Ferrite core 3... Gap 4... Sendust film 5... Gap spacer 6...・Bonding glass 1a... Roughened portion 1b... Mirror surface portion

Claims (2)

[Claims] (1) A magnetic head in which a sendust film is formed on at least one gap-opposing surface of two ferrite cores combined to form a gap, and the gap portion of both ferrite cores is bonded with bonding glass. . A magnetic head, characterized in that the gap facing surface of the core to which the sendust film is attached is roughened in a deep part, and the sendust film is also adhered and formed on this roughened part. (2) The magnetic head according to claim 1, wherein the surface roughening of the ferrite core is performed by etching, and the sendust film is adhered and formed on the surface of the ferrite core by sputtering.