JPS6233313A - thin film magnetic head - Google Patents

Abstract

PURPOSE:To attain simple assembling of a write head and a read head by forming a face being the adhesion between a flexible printed circuit board terminal and a thin film element conductor terminal onto the same face as the substrate and using the face to form a head matching face. CONSTITUTION:An insulation film 9 is formed on the substrate 1 and after an element conductor 6 is formed with a prescribed width together with elements on the film 9, an insulation film 10 is formed. In this case, Cu-Cr11 plating is applied to a part of the element conductor 6, the copper of an element terminal 7 is plated and the insulation film 10 is formed to adjacent terminals to obtain the element terminal 7. The element terminals 7 are formed at nearly 400mu pitch and the width of the terminals if formed by nearly 200mu, then a hole 12 through which an FPC conductor 8 is made in the element terminal 7 by etching and the surface of the substrate and the terminals is subject to finish processing. The pitch and the conductor width of the FPC conductor terminals 8 and the hole 12 of the element conductor terminals 7 are processed with high accuracy by etching and the hole 12 is used as a guide. Thus, the read/ write head are assembled incorporatedly easily.

Description

[Detailed description of the invention] [Field of application of the invention] The present invention relates to the structure of a thin film magnetic head #K.

The present invention relates to the structure of a thin film magnetic head suitable for drawing out signal lines from a substrate on which thin film elements are formed.

[Background of the invention]

The signal line extraction method for conventional thin-film magnetic heads was developed in 1973.
As described in Japanese Patent No. 8-69528, a substrate on which a thin film element is formed (hereinafter referred to as thin film element substrate 1) and a flexible printed circuit board 2 having signal lines connected to an external circuit are separately set. In order to connect each signal line (FIG. 2(a)), the structure was such that a large number of signal lines were connected one by one to a lead wire 5 using a wire bonder, as shown in FIG. 2(b).

In such a structure, advanced terminal processing technology is required for lead wire connection in multi-element high-density packaging, and it is expected that connection reliability will decrease due to the increase in connection points and wiring connection time will increase. .

In order to improve this structure, as shown in Figure 5 (α) Ch), the thin film element substrate 1 and the flexible printed circuit board 2 can be connected together by connecting a large number of signal lines, for example, by resistance crimp welding or infrared reflow soldering. It is possible to connect directly. However, in such a structure, for example, in the case of a head for a magnetic tape device (a head structure in which a write head and a read head are opposed to each other), one side of the thin film element substrate is used as the opposing surface, so a structure that allows the thickness of two printed circuit boards to escape is required. However, it is essential that the head structure is complicated.

To improve the head shown in Fig. 5, Fig. 4 (α) (b)
) is possible. This structure is described in Japanese Patent Application Laid-Open No. 128016/1982, and a thin film element substrate I is provided with a tapered portion that becomes deeper toward the end on the side where signal lines and terminals are provided, thereby forming a flexible printed circuit board. The structure is such that two parts are joined together. With this structure, as shown in Figure 4(b), a step of 50 to 100 microns from the board surface is created at the signal line terminal part, and the thickness of the printed circuit board is removed. It is also possible to integrate the head. However, forming thin film elements by forming steps on the thin film element substrate in advance is not necessarily easy considering the technology of forming a λ layer on a flat plate, which is a feature of thin film element formation technology, and it is difficult to achieve dimensional accuracy. It is desirable to be able to simplify and facilitate the formation of element circuits.

[Purpose of the invention]

The object of the present invention is to connect a conductor terminal drawn out from a thin film resistor to a printed circuit board terminal, and to provide a thin film a, which enables bonding on the same plane as the board and enables easy assembly of a write head and a read head. The aim is to provide a caring head.

[Summary of the invention]

In the case of forming a thin film element according to the present invention, a magnetic layer, an insulating layer, an electrode coil, and a signal line terminal must be laminated on the surface of a substrate, so that the signal line terminal is exposed on the surface of the substrate. For this reason, when a printed circuit board is connected to a signal line terminal, the printed circuit board protrudes from the surface of the circuit board, making it impossible to incorporate a read head and a write head. Therefore, in order to assemble the read/write head as one unit, it is necessary to make the element substrate surface the mating surface, and for this reason, the printed circuit board surface must be lower than the element substrate surface.

To do this, a hole is provided in the signal terminal surface of the element board, and by inserting the printed circuit board terminal into the hole, it can be positioned lower than the board surface.Then, the gap between the printed circuit board terminal and the hole is filled with soft brazing material. and connect the element board signal terminals and the printed circuit board terminals. Then, the element substrate surface is smoothed to form a mating surface.

By doing this, a mating surface can be formed with the printed circuit board and the element substrate bonded together, and the read head and write head can be assembled in the same manner as conventional heads.

[Embodiments of the invention]

An elliptical example of the present invention will be explained below with reference to FIG. FIG. M1 (cL) shows a state in which a thin film element substrate 1 and a flexible printed circuit board (hereinafter referred to as FPC) 2 are connected. The thin film element substrate 1 shown in this figure shows one block of a multi-track thin film magnetic head out of which a large number of head chips fabricated by a wafer process are integrated. The thin film element 5 is formed by laminating and processing an insulating film, a magnetic film, and a polar coil film on the substrate 1 using thin film forming techniques such as sputtering, plating, etching, and milling. The conductor terminal 7 is not connected to the coil of the thin film element 5 via the element conductor 6, but is formed by plating r) Cμ. On the other hand, for the flexible printed circuit board 2, FPe is often used to efficiently fabricate a large number of signal lines. After processing the conductor to the desired width,
FPe is produced by applying an insulating agent or adhering a polyimide cover thereon. The details of the method of bonding the thin film element substrate 1 and FPe2 fabricated in this way are shown in
) (c).

FIGS. 1(h) and 1(C) show the cross-sectional product and cross-section BB in FIG. 1(α).

An insulating layer q (S: 0.) is formed on a substrate 1, and an element conductor 6 is formed thereon together with the element. element groove.

In the body 6, an insulating film (AI!, O8) 10 is formed to insulate the vk adjacent element conductors formed with a predetermined width. At this time, in order to connect a part of the element conductor 6 to the element terminal 7,
Cr11 is also plated. Next, CtL of the element terminal 7 is plated, and an insulating film (A/, 0
．． ) 10 can be formed to obtain the element terminal 7.

The element terminal 7 has a pitch of approximately 400 microns and a terminal width of approximately 200 mm.
Formed in microns. After that, FPe necessary for the present invention
Etch a hole 12 into which the conductor 8 can be inserted into the element terminal 7. The hole 12 is approximately 100 microns wide and approximately 50-50 microns deep. The surface of the eroded substrate is finished, and the terminal surface is also finished.

The thin film can manufacturing process described above is carried out with the head chips integrated on the phenol substrate, and then the thin film shown in Figure 1 (cL) is cut out one block at a time as a multi-track thin film air-filling head. An element substrate 1 is produced. When separating one block at a time, process the escape step part 14 for the thickness of the FPC at the time of joining.
At the same time, the stepped portion of the terminal portion is processed so that Cμ of the terminal portion is exposed as shown in the cross section υ. Thereafter, the FPC conductor terminal 8 is inserted into the hole 12 of the element conductor terminal 7 and positioned as shown in FIGS. 1(A) and 1(c). The pitch and conductor width of the holes 12 of the FPC conductor terminals 8 and the element conductor terminals 7 must be precisely etched, and the holes 1
2 serves as a guide, which makes positioning easier than conventional positioning.

After positioning the FPC conductor terminals 8, the holes 12 of the element conductor terminals 7 are melted and filled with soft brazing material (e.g. solder 13) for bonding.In this way, the thin film element substrate 1 and the FPC 4 are
are joined. Figure 1(c) shows the cross section BB in the bonded state.
The thin film element portion 5 is omitted and only the terminal joint portion is depicted. To fix the substrate 1 and the FPCa, use the adhesive 15 at the stepped portion 14 to fix the FP (the conductor is covered with a resin or polyimide cover to protect the insulation. After this, to form a mating surface, One thin film head can be formed by finishing the surface of the 11i film cable substrate 1.

By using the FP bonding method described above, the head mating surfaces can be made flush, making it easier to assemble the read head and the write head.

In addition, it is possible to perform a large number of FPC connections at once, thereby reducing the number of connection steps and improving the reliability of the connections through filling bonding.

〔Effect of the invention〕

Conventionally, when an FPC, lead wires, etc. are bonded to a thin film element substrate, they become convex from the substrate surface and lose their function as a head mating surface.For example, when assembling a head for a magnetic tape device that integrates a read/write head, This necessitates a complicated head structure.

According to the present invention, even if an FP (,') is bonded to a thin film element substrate, the FPC does not protrude from the substrate surface, so the substrate surface can be used as a head mating surface, and read/write can be performed as before. The head can be integrated and easily assembled.

[Brief Description of the Drawings] Figure 1 shows an embodiment of the present invention, α) is an external view of the bonded state of the thin film element substrate and the FP (,'), and (b) is an A-A in Figure (α). Line sectional view, (C) is B- in (α) diagram
B-line sectional view, Figure 2 (α) is an external view of the conventional bonding state of the thin film element substrate and flexible printed circuit board, <b> is its side view, Figure 5 (α) (b) , Figure 4 (α) (b
) is an external view of the joined state of another method shown in FIG. 2 and a side view thereof. 1...Thin film element substrate 2...Flexible printed circuit board 5...Lead wire 5...Thin film element 6...Element conductor 7...Element terminal 8...FP(, 'Conductor terminal 9... Insulating film 10... Insulating film 11... Plating 12... Hole 15... Soft brazing material 14... Step 15... Seven inches

Claims (1)

[Claims] 1. In a thin film magnetic head in which a magnetic film, an insulating film, and an electrode coil are formed on a substrate using thin film technology, a surface where a flexible printed circuit board terminal and a thin film element conductor terminal are bonded on the same surface as the substrate. 1. A thin-film magnetic head characterized in that a magnetic head is present, and the surface thereof forms a head mating surface.