JPS62120612A - Production of laminated core for magnetic head - Google Patents

Abstract

PURPOSE:To improve workability by superposing a prescribed number of sheets of core leaves and preliminarily sticking a joining material consisting of a material which melts at the annealing temp. to the surface of the core leaves. CONSTITUTION:The joining material 10 is stuck to the surface of the core leaves 1 blanked to a prescribed shape in a pressing stage 21. A material selected from a nonmagnetic nonmetallic material such as, for example, SiO2 or Cu, Sn, Ti, Be or alloy of such nonmagnetic metallic materials is usable as the joining material 10. The core leaves are inserted into jigs and are arranged in the same direction and joined in a core arraying stage 22. The core leaves are annealed in an annealing stage 23. The joining material 10 consists of a material which melts at the annealing temp. of the core leaves 1 and therefore, joining of the core leaves 1 is executed simultaneously with annealing of the core leaves 1 if annealing is executed in the above-mentioned manner.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to a method for manufacturing a laminate core for a magnetic head.

"Prior art and its problems" As shown in FIG. 2, a magnetic head made of a laminate core is made by laminating a plurality of roughly U-shaped core thin pieces 1 made of magnetic material to form a core half 2. This is a method in which a pair of core halves 2 are butted against each other to form a magnetic gap 3 at the abutting surfaces, and has been widely used in the past.

This Core Half-Year 2 (laminate core) was manufactured by a process similar to a conventional method. First, a core flake 1 is produced through a pressing process and a barrel grinding process, and then the core flake 1 is annealed (annealed) as a single flake in an annealing process.The annealing is performed to improve the magnetic properties of the core flake 1. Next, in a core alignment process, the annealed core thin pieces 1 are inserted into a jig, aligned in the same direction, and brought into close contact. The tightly laminated core flakes l are then connected using a bonding material such as an adhesive or a synthetic resin, or by welding such as laser welding to form a core flake block.

Then, a core half 2 with a predetermined number of core flakes 1 joined together is cut out from this core flake block, and after adhering or inserting a gap forming material to the abutting surfaces of the core half 2, the core half 2 is combined into a pair. Butt them together to form a magnetic rad core. The gap-forming material is generally formed by inserting a thin piece into the gap-forming surface, or by sputtering, vapor deposition, or the like.

However, in this conventional method for manufacturing a laminated core, when the core flakes l are bonded using bonding materials such as adhesives and synthetic resins, the heat resistance temperature of these bonding materials is at most 2.
Since the temperature is as low as around 50°C, sputtering, vapor deposition, etc. for attaching the gap-forming material deteriorate bonding properties and magnetic properties.For example, in sputtering, the processing temperature reaches as high as 700°C to 750°C.

On the other hand, when the core flakes 1 are joined by welding, two or three locations of the core flakes 1 are welded and at least one of the locations is subsequently removed in order to reduce eddy current losses. However, removing the welded portions of the core thin pieces 1 once joined in this manner is not easy to work with, and the generation of eddy currents due to welding cannot be completely eliminated.

``Object of the Invention'' The present invention solves the problems of the conventional laminate core manufacturing method, has excellent magnetic properties and workability, and improves the magnetic properties and bondability of core thin pieces by adhering a gap-forming material. An object of the present invention is to obtain a method for manufacturing a laminate core that does not deteriorate.

"Summary of the Invention" The present invention is based on the fact that an annealing process is essential for improving magnetic properties in the manufacturing process of a laminate core, and that this annealing process is performed at a high temperature of around 1100°C. This research was completed with the idea that it could be used to join core flakes. In other words, the method of the present invention improves the conventional method in which the core flakes are first annealed as a single piece, and also uses the method as a joining material for joining the core flakes.
A material that melts at the annealing temperature is selected, and this bonding material is attached to the surface of the core flakes, and then the core flakes are stacked and annealed in that state, so that annealing and bonding of the core flakes can be performed at the same time. It is characterized by the fact that

The present invention also proposes a manufacturing method that can easily and efficiently apply a uniform gap-forming material to the core halves.

``Example of the invention'' The method of the present invention, each step of which will be explained below based on the drawings, is as follows:
As shown in FIG. 1, a bonding material 10 is attached to the surface of a core thin piece 1 punched into a predetermined shape in a pressing step 21. As shown in FIG. It is preferable from the viewpoint of workability that the bonding material 10 is attached to the material of the core thin piece 1 in a bonding material attaching step 20 prior to the pressing step 21. This bonding material lO is applied to the front and back sides of the core thin piece (material) 1 to which the material 10 is attached.
Adhesive formation has the advantage that directionality can be eliminated. The bonding material 10 may be a material that melts at the annealing temperature of the core flake l, such as a nonmagnetic nonmetallic material such as SiO2, or a material selected from Cu, Sn, Ti, Be, or an alloy of these nonmagnetic metallic materials. I can do it. Moreover, this bonding material 1O can be specifically deposited and formed by sputtering, vapor deposition, plating, coating, or the like. Furthermore, if an oxide film is formed on the surface of the core flake 1 before attaching the bonding material 10 to the surface of the core flake 1, mutual diffusion will occur between the oxide film and the bonding material 10, which will make it stronger. Core flake l and bonding material l
Can be joined with O.

The core thin pieces 1 with the bonding material 10 adhered to their front and back sides in this manner are then inserted into a jig in a core alignment step 22, and are aligned in the same direction and brought into close contact with each other.

The bonding material 10 is always interposed between the tightly laminated core thin pieces 1.

This laminated core thin piece l is then annealed (
During this annealing, an appropriate pressure in the lamination direction is applied to the laminated core thin pieces 1. When annealing is performed in this manner, since the bonding material 10 is made of a material that melts at the annealing temperature of the core flakes 1, the core flakes 1 are bonded at the same time as the core flakes 1 are annealed. For example, when Permalloy or Sendust is used as the core flake l, the annealing temperature is 1100°C to 1150°C.

Core flake block 1 formed in this annealing process 23
1 is then left as a block and its gap surface (butting surface) 12 is polished in a gap surface polishing step 24, and a gap forming material 13 is deposited on this gap surface 12 in a gap forming step 25. As the gap forming material 13, the same material as the bonding material 10 can be used, and its forming method includes sputtering, vapor deposition,
A conventionally known method such as plating can be used.

It is said that by polishing the gap surface 12 of the long core flake block 11 and attaching the gap forming material 13 thereto, the work efficiency is high and a flat and uniform gap forming material 13 can be obtained. There are advantages. Furthermore, since the joining material 10 that joins the core flakes l has higher hardness than resin materials or adhesives, the gap surface 1
2 can be maintained at a high level. Furthermore, since the bonding material IO does not melt at the temperature at which the gap forming material 13 is formed, it is possible to similarly increase the flatness of the gap surface 12 and shorten the working time by increasing the processing temperature. can.

This core flake block 11 is cut into core halves 2 having a predetermined number of core flakes l in the next cutting process 26. Then, in the head assembly step 27, the pair of core halves 2 are butted against each other, and a magnetic gap 3 is formed by the gap forming material 13 on the abutting surfaces.

"Effects of the Invention" As described above, the method of the present invention performs annealing, which was conventionally performed on a single core flake, by stacking a certain number of core flakes, and the surface of the core flake is made of a material that melts at the annealing temperature in advance. With the bonding agent deposited, the core flakes can be annealed and bonded at the same time. Therefore, it is possible to improve the magnetic properties and improve workability, contributing to the automation of the production line for laminated cores. In addition, when attaching the gap forming material after polishing the gap surface, since the bonding material has sufficient high temperature resistance and hardness, it is possible to increase the flatness of the gap surface and improve the magnetic properties. can. The gap surface is polished and the gap-forming material is applied to the core flake block formed by annealing and processing, and then a predetermined number of laminated cores are cut out for each core flake. The efficiency of material adhesion work can be improved. Furthermore, by increasing the flatness of the gap surface and making the thickness of the gap forming material uniform, it is possible to obtain a laminate core with excellent performance and consistent characteristics.

[Brief explanation of drawings]

FIG. 1 is a block diagram including a schematic diagram showing the state of a core flake (core flake block), showing the steps of the manufacturing method of a laminate core for a magnetic head according to the present invention; FIGS. 2(a) and (b)
1 is a perspective view of a laminate core and a plan view of a magnetic head. l...Core thin piece, 2...Core half-closed (laminate core), 3...Magnetic gap, 10...Joining material, 11
... Core flake block, 20 ... Bonding material adhesion process. 21...Press process, 22...Core alignment process, 23
... Annealing process, 24... Gap surface polishing process,
25... Gap formation step, 26... Separation step,
27...Head assembly process. Patent applicant Alps Electric Co., Ltd. Agent Kunio Miura Shigeru Matsui Figure 2

Claims (4)

[Claims] (1) In a laminate core for a magnetic head in which a plurality of core flakes that are annealed to improve magnetic properties are laminated and bonded via a bonding material interposed between the core flakes, the bonding material is bonded to the core flakes. Select from materials that melt at an annealing temperature of A method of manufacturing a laminated core for a magnetic head, the method comprising bonding two core thin pieces. (2) In claim 1, the core flake is made of permalloy or sendust, and the bonding material is Si.
Non-magnetic non-metallic materials such as O_2, or Cu, Sn, Ti
, Be or an alloy of these nonmagnetic metal materials. (3) In a laminate core for a magnetic head in which a plurality of core flakes that are annealed to improve magnetic properties are laminated and bonded via a bonding material interposed between the core flakes, the bonding material is bonded to the core flakes. Select from materials that melt at an annealing temperature of A core flake block is formed by bonding the core flakes, and then, after polishing the joint surface of this core flake block, a gap forming material is attached, and then the core flake block is cut into a predetermined number of core flakes. A method for manufacturing a laminate core for a magnetic head. (4) In claim 3, the core flake is made of permalloy or sendust, and the bonding material is Si.
Non-magnetic non-metallic materials such as O_2, or Cu, Sn, Ti
, Be or an alloy of these nonmagnetic metal materials.