JPS58122610A - Magnetic head - Google Patents

Abstract

PURPOSE:To prevent the deterioration of a corner at slicing, by depressing the front part of a magnetic head chip than the rear part and specifying the range of depression. CONSTITUTION:The front part 23 of the magnetic head chip 20 is depressed than the rear part 33, that is, a step 35 is formed. This step 35 is formed, by slicing a block 39 over 35-45% of the entire height with the 1st blade 41 having a large blade thickness t1 to form the front part 32 and shaping the block 39 with the 2nd blade 42 having a small blade thickness t2 to form the rear part 33. Thus, the two-stage of cuttings are performed with the blades having different blade thickness and the 1st cutting is taken in the range of 35-45%, allowing to make the heat dissipation from the cut point easy and to reduce deterioration such as cracks, breaks and chipping.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a magnetic head suitable for densely recording and reproducing high frequency signals such as in a VTR.

A typical VTR magnetic head chip consists of magnetic wafer halves 117 +21 facing each other with an operating gap length between them, and a non-magnetic bonding material (for example, glass moon 51) being filled in defined grooves +31 +41 in the tracks between them. This block (6) is fixed to the base (7) with a removable adhesive, and the blade thickness (
8) by slicing with a cutter (see FIG. 1; the hatched portion surrounded by broken lines indicates the portion removed by the cutter).

However, in slicing, the cutter must be sent deeper than the entire length uG of the magnetic head chip (9), and the blackening from the grinding point is not sufficiently achieved.
As a result, the surface condition of the ground surface deteriorates (for example, if the magnetic material
n-Zn ferrite, Ni-'Zn ferrite, etc., have the disadvantage of causing cracks, cracks, or smudges. In order to reduce this deterioration, it is conceivable to polish the finely ground surface in post-processing. However, this has the disadvantage of not only the workability but also the need to provide a margin for the polishing during slicing. On the other hand, at the corner of the tape contact surface and the grinding surface of the magnetic head chip, a second
As shown in the partially enlarged figure, first, there is a shallow groove ful.
A method has been proposed in which a groove I is formed and a deep groove surface for slicing is formed using the groove I as a guide. Even with this method, the above deterioration cannot be avoided when forming the deep grooves az.

The present invention aims to provide a new magnetic head based on a new slicing method that eliminates this deterioration.

That is, in the present invention, on the side surface (ground surface) of the magnetic head chip that faces the base that supports the magnetic seven dots,
In a magnetic head having a step in which the front part on the tape contact surface side falls down compared to the rear part, the ratio of 1 (=A/B) to the total length B1 of the front part A is 35 to 45. It is an object of the present invention to provide a magnetic head which is characterized in that the magnetic head can be selected within a range of 30 degrees. The slicing method for producing magnetic rad chips uses a peripheral slicer with a blade thickness of t1.
A diamond blade 11 is used to grind 35 to 45 degrees of the height of the block to the molecular rt, and then a blade 11 smaller than the groove width of this grinding groove, that is, smaller than the blade thickness t1.
The remaining portion of the grinding groove is ground and cut from the bottom of the groove using a diamond blade of No. t and 2. In this way, the above-mentioned step is formed within the grinding surface. The grinding surface of this magnetic herad tip is the above-mentioned No. 1. It has been found that since the molding is performed by the second-stage grinding operation, the incidence of surface deterioration can be significantly reduced. In addition, the above ratio R
The reason why is set in the above range is that if it exceeds 45%, it will be difficult to make the grinding surface of the second stage of the magnetic herad tip into a gap when the magnetic herad tip is attached to the support base.
The probability that the magnetic head chip will be mounted diagonally to the support base is high (on the other hand, if it is less than 35%, the second stage cut depth will be large and it will be difficult to dissipate the grinding heat). This is because the incidence of the above-mentioned deterioration increases.

Next, the present invention will be explained according to illustrated embodiments. FIG. 6 is an external perspective view of the magnetic held tip of this embodiment, and FIG. 4 is a partial side view showing how the magnetic hent tip is attached to the support base. The magnetic head chip is made of Mn-Zn ferrite single crystal core half-holes 1211Q2 arranged apart by a predetermined gap length, and C is formed into a defined groove in each core half-hole. (For example, it is integrated by filling it with glass.

Then, the tape contacting surface (2) of the chip is adjusted to a predetermined track measure (so that it is sufficiently wide in the center).One core is half-closed, and a coil winding window (toward) is drilled there. This window is used to wind a coil (not shown) in a so-called balance winding.The upper edge of this window is hidden by a coupling tool in the figure, but the lower end of the operating gear holder is The side surface C11l, which is the magnetic path forming surface of the chip and faces the support base (to), has a front part (to) close to the tape contact surface (to) and a rear part far from the relevant contact surface. It is provided with a slope (end) separating the support and these along the track extension direction.As shown in the figure, the front part (support) is configured to fall down compared to the rear part (end). In this embodiment, the step height C is set to 30 to 50 PIn.Here, the ratio 1 ((==^/B) of the height A of this front part (toward) to the total length B is as described above. 35U top, 0.
It is set to 45 or less. This magnetic 7-dot chip I is placed on the support base ■ as shown in Figure 4, and the adhesive
Fixed by At this time, since the center of gravity of the chip (111) is at the rear (end), the tip (111)
Can be installed parallel to the surface of the Incidentally, the window (2) is placed in front of the tip (-) of the support base (to) so as not to interfere with the winding work in the next step.

FIG. 5 shows an embodiment for forming the step. In the figure, (support) is a block similar to that shown in Figure 1, ■ is a base that supports the block, 41H4Z
is the first step for cutting out the magnetic head tip and knob from the block. This is the second blade. 181 blade I has a large blade thickness t1 (for example, 10
0-150P) With a diamond blade, slice the block country over 35-45% of its total height with the first blade.

The I82 blade is a die Ymond blade with a small blade thickness t2 (for example, 70 to 100μ) for forming the rear part (end), which allows the remaining part to be removed from the bottom (rotation) of the groove by the first blade. Grinding and cutting. At that time, as shown in the figure (cut the center part of the first stage of abrasive grooves), the grain size of each blade (a) is adjusted to
It is necessary to be fine grained over 24011, while◆
If the grain size is more than 400, the amount of grinding heat generated is large due to insufficient grinding ability, and deterioration such as cracks, cracks, and swells are likely to occur.

Because of this, the grain size of each blade is 9240 ~
φ525 is suitable.

In this way, the blades are divided into two stages with different thicknesses.
By setting the IR in the range of 35 to 45% of the total, heat dissipation from the grinding gt+ point becomes easy and the deterioration of the conventional example can be reduced. In the experimental example, the above-mentioned inferiority was observed in 12% of the head chips obtained by two-pass chip slicing with a conventional peripheral slicer, but in the present invention, 0.
．． It turns out that the decline will be 8%. Further, in the magnetic head of the present invention, when the support base of the magnetic head chip is attached, the adhesive side can be filled in the space between the magnetic head chip and the support base due to the step, and the chip can be firmly fixed.

[Brief explanation of drawings]

FIG. 1 is a perspective view of the configuration of a magnetic block for explaining the conventional slicing method, and FIG. 1J2 is a partial perspective view of another conventional slicing method. FIG. 3 is a perspective view II of the structure of a chip constituting the magnetic head of the present invention, and FIG. 4 is a side view showing the state in which the chip is fixed to a support base. @Figure 5 is an explanatory diagram of the slicing method for obtaining the magnetic head of the present invention. Explanation of main drawing numbers (Kai...magnetic head chip, Cl1l...magnetic path configuration surface (opposite side), @...front part, (Foundation)...rear part, vessel...step, Mountain...Support base. Figure 4 Figure 6 Proceedings Amendment (spontaneous) March 2, 1980 To the Commissioner of the Patent Office 1, Indication of the case Patent Application No. 5225 of 1988 2, Title of the invention 115 [Head 6, Person making the amendment Patent applicant Address: 2-18 Keihan Hondori, Moriguchi City Name (188) Sanyo Electric Co., Ltd. Representative: Kaoru Iue 4, Agent address: 2-18-5 Keihan Hondori, Moriguchi City , Target of amendment (1) Column [Detailed description of the invention j] in the specification. 6. Contents of amendment fi+ #4 On page 6, line 8 of the specification, [For example, 100~
150 μm” to [for example, 200 to 250 μm”]. (21 (b) No. 61, line 12, “For example, 70 to 100
Correct μm1 to “for example, 150 to 200 μm”. 9th grade

Claims (1)

[Claims] +11 In a magnetic head, the side surface of the magnetic head chip facing the base supporting the magnetic head chip is provided with a step that is lower than the front part or the rear part on the tape contact surface side. , the ratio it of the front part A to the total length B
(=l=A/B), and α35≦R10,45.