JPH02149902A - Production of magnetic head - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a method of manufacturing a magnetic head used in a magnetic recording/reproducing device such as a VTR.

(Prior Art) A conventional magnetic head used in a magnetic recording/reproducing device such as a VTR is known, for example, as shown in the vertical cross-sectional view of a conventional magnetic head in FIG. This conventional magnetic head is
A ferrite chip 50 is a magnetic chip having a tape sliding surface 50a and a coil winding portion on the tip side, and is then fixed with an adhesive 52 on a substrate 51 made of brass or the like on the layer side. There is. As the adhesive 52, an instant adhesive or the like is used.

When viewed in plan, the ferrite chip 50 has a gap filled with ceramics or the like and having a width of 1 μm or less formed at its tip side, and the magnetic poles are projected differently across this gap. Further, a wire 53M for the coil 53 is formed in the coil winding portion for converting an electric signal into a magnetic signal and vice versa. The end of this coil 53 is
It is connected to a circuit board 54 attached to the back surface of the board 51. In addition to inputting and outputting electrical signals to and from the coil 53 via this circuit board 54, it also protects the adhesive 52 made of an instant adhesive with relatively low moisture resistance, fixes the formed coil 53, and Coil 53 for the purpose of reinforcing the adhesion of the ferrite chip 50, etc.
The adhesive area of the ferrite chip 50 and the surrounding area of the substrate 51 are covered with a molding material 55 made of boxy resin, acrylic resin, or the like. The molded material 55 is formed by bodding epoxy resin, acrylic resin, etc. with a dispenser or the like so that it reaches the coil forming position after forming the coil 53, and then hardening it. Therefore, the cold material 55
As the resin for forming the film, one that is initially in a liquid state and hardens when exposed to heat, ultraviolet light, or left at room temperature is used.

However, the total magnetic head has 50 ferrite chips.
50 a Toko 1 53
The distance between the winding position and the winding position is about IW or less, and the two are very close to each other. For this reason, when potting the resin for forming the mold material 55, it flowed out onto the tape sliding surface 50a due to variations in the amount of botting. However, due to this error of ±0.2 cape, the resin may flow out to the tape sliding surface 50a1, and the resin, which is an organic substance, may solidify in a portion of the tape sliding surface 50a.
When the tape is used for sliding, there is a problem in that not only a sufficient output cannot be obtained, but also the tape may be seriously damaged.

(Problem to be Solved by the Invention) As described above, in conventional magnetic heads, the distance between the Dave sliding surface and the winding position of the coil is very close to each other at a distance of about 1 wa or less. When potting,
Variation in the amount of botting (this caused the resin to flow out onto the sliding surface of the chip, which not only resulted in insufficient output when sliding against the tape, but also caused serious damage to the tape) .

The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a method for manufacturing a magnetic head that can reliably obtain magnetic fields with good characteristics.

[Structure of the invention]

(Another Means for Solving the Problems) In order to achieve the above object, the method for manufacturing a magnetic head of the present invention includes manufacturing a magnetic head on the rear end side of a magnetic chip having a tape sliding surface and a coil turning section on the front end side. A process of adhering to the substrate,
There is a step of winding the wire for the coil around the coil winding section, a first application step of applying resin only to the wire winding section, and a first step of curing the applied resin. a curing step, a second coating step of applying a resin in an amount equal to or greater than the amount applied to the adhesive portion between the magnetic chip and the substrate on the side away from the tape sliding surface with respect to the applied portion; The gist is Kokichi, which includes a second curing step of curing the applied resin.

(Function) In the method of manufacturing a magnetic head according to the present invention, a resin is applied with a slight H on the coil at the tip of the magnetic chip, and after the resin is once hardened, the magnetic chip and the substrate are coated. By applying resin to the old adhesive and curing it, the resin is prevented from leaking onto the tape sliding surface of the magnetic chip, improving head characteristics.

(Example) Hereinafter, an example of the present invention will be described with reference to the drawings. 1st
The figure is a longitudinal sectional view of a magnetic head according to an embodiment of the invention.

In the figure, the magnetic head l has a ferrite chip 2 as a magnetic chip equipped with a 1/1H1Jζ chip sliding surface 2a and a coil winding portion, and a rear end portion made of brass or the like. It is fixed with an adhesive 4 onto a printed substrate 3. As the adhesive 4, an instant adhesive or the like is used.

When viewed in plan, the ferrite chip 2 is designed such that a gap having a width of 1 μm or less is formed on the tip side thereof and filled with ceramics or the like, and the magnetic poles differ across this gap.

Further, the coil winding portion 1 is formed with a wire 5a for the coil 5 for converting an electric signal into a magnetic signal and vice versa. The end of this coil 5 is connected to a circuit board 6 attached to the back surface of the board 3. Coil 5 via this circuit board 6
Electrical signals are input and output.

Furthermore, in order to fix the formed coil 5, a molding material 7 made of epoxy resin, acrylic resin, etc. is placed on the coil 5.
a is covered. In addition, for the purpose of protecting the adhesive 4 made of an instant adhesive with relatively low moisture content and reinforcing the adhesion of the ferrite chip 2, the adhesive area of the ferrite chip 2 and the parts of the substrate 3 around it are made of epoxy resin, acrylic resin, etc. It is covered with a molding material 7b. The molding material 7a is formed by potting epoxy resin, acrylic resin, etc. only onto the coil 5 using a dispenser or the like after the coil 5 is formed, and then hardening it. The adhesive area and the portion of the substrate 3 around it are bonded and then cured. Therefore, the resin used to form the molding materials 7a and 7b is one that is initially liquid and hardens when exposed to heat, ultraviolet rays, or left at room temperature.

Next, the manufacturing process of the above-mentioned magnetic head 1 will be explained using the process diagram of the magnetic head according to the embodiment of the present invention shown in FIG. 2 and the flowchart of the magnetic head according to the embodiment of the invention shown in FIG. Note that each item symbol in the following explanation corresponds to (a) to (g) in FIG. 2, respectively.

(a) A substrate 3 of a desired shape is prepared from brass or the like.

(b) The rear end side of the ferrite chip 2 is attached and fixed onto the substrate 3 using an adhesive 4 made of instant adhesive (step 21).

(C) The wire 5a is wound around the coil winding portion of the ferrite chip 2 (step 22).

(d) Using the syringe 10, a small amount (0.05 to 1 cape) of resin 7a for molding material is potted only on the coil 5 on the tip side of the ferrite chip 2 (step 2).
3). The resin 7a is an ultraviolet curable acrylic liquid resin "TB-3031" (manufactured by Three Bond ■).
was used.

(e) While transporting the magnetic head 1 formed and processed as described above on the belt conveyor 11, UV lamp 12 is used to irradiate the magnetic head 1 with ultraviolet rays to harden the resin 7a (step 24).
.

(f) In the same manner as in (d) above, use the syringe 10 to apply a bond between the ferrite chip 2 and the substrate 3 on the rear end side of the ferrite chip 2 on the side away from the tape sliding surface 2a.
Resin 7b for molding material is potted (step 25). As the resin 7b, an ultraviolet curing type acrylic liquid resin 1'-TB-3031J (manufactured by Three Bond ■) was used.

(g) Resin 7 for mold material in the same manner as in (e) above.
While transporting the magnetic head l on which b was botted on the belt conveyor l, ultraviolet rays were irradiated with the UV lamp 12 to harden the resin 7b, thereby completing the magnetic head 1 (step 26).

The magnetic head 1 formed in this manner has a barrier layer formed of the resin 7a for molding material on the coil 5 by the first potting process (first coating process). Even if a large amount of resin 7b for molding material is botted in the step botting process (second coating process), the resin 7b can be prevented from flowing out to the tape sliding surface 2a. Furthermore, the measurement results showed that the amount of botting of the resin 7a for the molding material in the first stage was very small (approximately 0.3 # in this example), and the error was approximately ±0.041F. Therefore, the conventional error of ±0.2jlF has been reduced to ±0.04jF with this method,
As a result, the tape sliding surface 2 of the resin 7b for molding material
A magnetic head 1 can be obtained which can prevent leakage to a and has excellent electromagnetic characteristics. Moreover, these improvements can improve yield and performance in manufacturing the magnetic head 1.

〔Effect of the invention〕

As explained above (according to Koki-nii IJ!:i), a small amount of resin is applied onto the coil at the tip of the magnetic chip, and after the resin is cured for a few degrees, the magnetic depth and the substrate are bonded together. By applying resin to the adhesive part and curing it, it is possible to prevent the resin from flowing out onto the tape sliding surface of the magnetic material depth, and to obtain a magnetic head with good electromagnetic characteristics. .

[Brief explanation of the drawing]

Claims (1)

[Claims] A step of adhering the rear end side of a magnetic chip having a tape sliding surface and a coil winding part on the front end side to a substrate, and winding a coil wire around the coil winding part. a first coating step of coating the resin only on the wire winding portion; a first curing step of curing the applied resin; and a tape sliding step on the coating portion. a second coating step of coating the adhesive portion of the magnetic chip and the substrate on the side away from the surface with a resin in an amount equal to or greater than the coating amount; and a second curing step of curing the coated resin. A method of manufacturing a magnetic head, comprising: