JPS5817530A - Manufacture of magnetic head core - Google Patents

Abstract

PURPOSE:To realize tight connection between a couple of core half blocks without deteriorating magnetic characteristics, and to obtain high gap strength, by depositing an alloy soldering layer for the connection. CONSTITUTION:A core half block 1 is made of ''Sendust '' alloy and has groove parts 2 and 3. The surface including the groove parts 2 and 3 is polished into a specular surface, and quartz glass films 5 and 6 are formed on said polished surface at both ends. The other core half block 4 is made of the same material with the block 1 and has quartz glass films 7 and 8. Each film is a half as thick as gap width W. Alloy soldering films 12 and 13 are formed by sputtering on the butting surfaces of the blocks 1 and 4 which correspond to rear-part gap parts. The material of the alloy soldering films favorably contains, for example, Ag (40-50%), Cu (15-19%), Zn (15-21%), and Cd (18-20%). The core half bodies 1 and 4 having the alloy soldering films 12 and 13 butting against each other are connected together by being heated in a vacuous or argon atmosphere at >= about 100 deg.C higher than the liquid-phase temp. of the alloy solder.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a magnetic helad core by joining a pair of core and semi-dead blocks of a magnetic material. A solder alloy layer is formed in advance on at least one of the flat surfaces between the pair of grooves or the opposite surfaces thereof, and the core block is created by joining each half-core block by melting the solder alloy layer. The purpose of the present invention is to provide a method for manufacturing a magnetic core that has a narrow gap width and can improve mechanical strength.
Techniques for recording at lj degrees have been developed, and a narrow gap width, narrow track magnetic head for high density recording is being developed using Sendust alloy.

Conventional manufacturing method of magnetic helad core with metal magnetic material (
1) is a method in which, for example, the abutting surfaces of a pair of sendust core semi-dead blocks having a predetermined shape are joined using alloy solder, and the gap width is further formed by the thickness of this alloy solder. In this manufacturing method, (1) it is difficult to control the gap and tends to cause variations in the gap width; (2) the edges of the gap are likely to sag due to running of the magnetic tape, causing deterioration of the magnetic head characteristics. There are drawbacks such as.

Another conventional magnetic herad core manufacturing method (2) is described in the first
This will be explained with reference to FIGS. 11 to 3. First, substantially trapezoidal grooves 2.3 are cut from both ends of the rectangular parallelepiped core half-block 10 into the respective lids at predetermined positions. The groove SFi has a slightly larger shape than the groove 2 since a coil will be wound therein in the future.

Next, each mating surface 1a of the core half-closed block 1゜4
, 4a are mirror-polished, and as shown in FIGS. 1 and 2, a quartz glass film 5, having a predetermined length and half the thickness of the gap width W, is formed on both end surfaces of the mating surfaces 1a and 4m, respectively. 6
Form ゜7.8. Quartz glass membrane! ,6. T, @.

is formed by a thin film forming means such as vapor deposition or sputtering, and a highly accurate film thickness can be obtained.

The rectangular parallelepiped blocks 1.4 are brought together and the alloy solder rods 9, 101r are inserted into the grooves 2.3, as shown in FIG. 3. After that, the whole rectangular parallelepiped block 1.4 is made of alloy wax rod.
, 10 is heated and pressed above the temperature. The 0 alloy solder rod 11 melts and flows into the rear gap 11 formed by the blocks 1 and 4 to join the blocks 1 and 4, forming a core block. Ru. The magnetic helad core manufactured by the above method (2) has good gap width accuracy, and there is no sagging at the gap portion, so that the magnetic head characteristics do not deteriorate. However, the above manufacturing method (!1) is based on the alloy stomach rod 9
is difficult to melt and sufficiently flow into the rear cavity 11,
Therefore, the joint strength between both blocks 1.4 becomes insufficient. In addition, when the four alloy solder rods 9 and 10 are heated and pressed at a temperature much higher than that in order to sufficiently flow the alloy solder into the rear cavity 11, the alloy solder will thermally diffuse into the sendust core, causing the sendust There were drawbacks such as deterioration of the magnetic properties of the core.

The present invention eliminates the above-mentioned drawbacks, and an embodiment thereof will be described with reference to FIG. 4 and subsequent figures. In each figure, parts b that are the same as those in FIGS.

First, the core semi-circular block 1 is a rectangular parallelepiped (made of a metal magnetic material such as Sendust alloy), and the block IK is manufactured using the conventional manufacturing method (21). Cut along the direction St+. Next, the surface of this block 1 having the groove portion 2.3 is polished to a mirror finish, and a quartz glass film 5. is formed on both end surfaces of this surface in the same manner as before. .

In addition, the core half-closed block 4 is made of the same material as the block 1, and the mating surface with the flock 1 is mirror-polished.
On both shoulders of this surface, quartz glass films T and I are formed opposite to the quartz glass films S and 6.

Quartz glass film 5. @, 7. The thickness of s is half the gap width W.

Next, as shown in FIG. 4 and FIG.
On the portions to be polished, alloy wax films 12 and 13 are formed as alloy brazing layers, which are the essential part of the present invention, by a slatting method. The thickness of the alloy film 12゜13 is the thickness of the quartz glass films s, s, y, s W/! Make it a little thicker. Alloy wax film 12. The IS material is, for example, mug (40%),
Cu (11-19%), Zn (15-21%), 0
(1 (121-2g19G), and iltAg
(45~5@%), Cu(22~2@%L Zn(I
T~28%), 8n (2~S%) f), and HAg (40~50%) Ou(114o*)Z
n (15-21%), N1 (3-5%) - so,
Good for bonding with Sendust alloy in terms of tensile strength, brazing temperature, etc. Also, the alloy wax film 12. The sputtering method used as a forming method for 'ts is suitable for forming films because the sputtered particles themselves are alloyed even when the alloy wax is formed into a film, so the composition change rate between the base material and the film is extremely small. ing.

Next, the slope [2a, $a of the groove 2.3 of the block 1 is made to be on the lower side, and the block 1.4 shown in FIGS. Roku Membrane 12.
13 so that they face each other, and the alloy rods 10 are inserted into the grooves 2.8 as shown in FIG. The materials of the alloy solder rods 9 and 1o and the alloy solder film IL13 are the same. After this, pressure is applied from both sides of each block 1.4 and the alloy solder l1lt2. ts and heated in a vacuum or argon gas atmosphere to a temperature approximately 10 PCs higher than the liquidus temperature of the alloy solder. By melting @t 2, 13 and diffusing an appropriate amount with sendust, blocks 1,
4 are firmly joined. The alloy solder rod is melted to form a joint part 14 integral with the alloy solder films 12 and 11, and the quartz glass film 1. Adhere TYr. The alloy wax rod 10 has a quartz glass film S.

8 and fix the gap portion 1s. The gap IS is made of quartz glass! , I is formed, and by having the quartz glass films II, T), an accurate gap width W with no inclination in the longitudinal direction of the gap portion 15 can be obtained. Therefore, a b core block 1@ having a narrow gap with good precision and a high bonding strength between the blocks 1 and 4 is created.

Next, the core block 16 is sliced along rHK shown by a dashed line in FIG.
A magnetic helad core 11 having the track width t shown in the figure is obtained.

Magnetic helad core 17i obtained as described above, as shown in Figure aS, wear-resistant non-magnetic glass on both sides, 7
Reinforcement plates ts and ts' such as Otoceram Macor are bonded with adhesive, and the tape becomes the running surface f as shown in Figure 10.
I! The contact surface II is polished into an arc shape. By polishing and forming the magnetic helix 9 to a predetermined gap depth L, a magnetic helical core 2 can be obtained, and the manufacturing of the magnetic helix core 2 is completed.

Incidentally, in place of the alloy film 12.11 formed by sputtering in FIGS. 4 and S, thin strip-shaped alloy wax sheets 21 are sandwiched between blocks 1.4 as shown in FIG. It is okay to join.

The magnetic head iron j manufactured according to the present invention has high mechanical strength, a narrow track, a narrow gap width, and is made of a metallic magnetic material (for example, Sendust alloy) with a high saturation magnetic flux density. Since Sendust alloy is used, the small specific resistance of Sendust alloy (A) reduces eddy current loss due to K, and the effective magnetic permeability of the Sendust alloy core in the video band is improved, making it possible to improve the frequency characteristics of playback sensitivity. . Therefore, the magnetic Herakoama 10 can be used for recording and reproducing video signals, etc. of a video tape recorder using a high-magnetic magnetic tape, a so-called metal tape.

As described above, the method for manufacturing a magnetic helad core according to the present invention is to prepare the flat surface between a pair of grooves formed by fitting a pair of core semi-dead blocks and the latches on one side, or the opposite WiK, beforehand using an alloy. In order to form a solder layer and join a pair of half-core blocks by melting the alloy wax layer, it is possible to firmly and reliably join a pair of half-core blocks without deteriorating the magnetic properties. A magnetic rad core with a narrow track and narrow gap having high gap strength can be obtained, and has the following features.

[Brief explanation of drawings]

FIGS. 1 to 3 are perspective views of a half-dead core structure for explaining each manufacturing process of a conventional magnetic herad core, and FIGS.
Figures to Figures 10 are perspective views of a core cow body and a core block for explaining each manufacturing process of one example of the method of the present invention, and Figure 11 is a perspective view of a part of another embodiment of the method of the present invention. Manufacturing worker 1
It is a perspective view of the core cow body block of. 1.410. Core half-day block, 2. Mizobe, S. 11,? , 11: Quartz glass film, ■, 1: Four alloy bars, 12.13: Alloy base film, 1: Gap portion, 16: Core block, 2 (1... Magnetic helad core, 21301 alloy wax sheet.

Claims (1)

[Claims] (Major) A pair of grooves are formed in at least one abutting surface of a pair of core semi-dead blocks made of a pair of magnetic materials at a predetermined distance from both ends of the abutting surface along the longitudinal direction thereof. Then, a non-magnetic film is formed to form a gap on both ends of the mosquito groove on the mosquito contacting surface, and the pair of core half blocks are joined together to create a core block. Method of manufacturing magnetic helad core>
%/h, forming an alloy solder layer on at least one of the flat surfaces between the shell grooves or the flat surfaces opposite thereto, and placing the alloy brazing rods in each shell groove with the core half-dead blocks brought together;
1. A method for manufacturing a magnetic helad core, which comprises forming a core block by joining a pair of wrinkled core semi-dead blocks by melting the wax alloy layer and the wrinkled alloy wax rod by heat-pressing. (2) The wax layer is deposited on the flat surface of the cough core (
a) The cylindrical alloy layer is adhered to the flat surface of the half core.