JPS58182120A - Manufacture of multichannel thin film magnetic head - Google Patents

Abstract

PURPOSE:To connect a conductor terminal pattern to a flexible wire easily by providing a terminal electrode for electrodeposition connected to a head element simultaneously with the formation of the head element. CONSTITUTION:An insulator layer 11 is formed on the surface of a magnetic material substrate 1; and a high resistance material is vapor-deposited thereupon with a mask, and a ferromagnetic material is vapor-deposited. Then, a bias layer 12, magneto-resistance effect element 13, monitor element 13' for tape sliding surface work, terminal 20 for electrodeposition, and mark 21 for tape sliding surface grinding work are formed at the same time by photoetching. The magneto-resistance effect element 13 and one end of the monitor element 13' are connected to the terminal electrode 20 for electrodeposition and a conductor terminal pattern 14 of a conductive material such as Au for a lead connection is formed so that the one end of the element 13' can be connected directly to the electdrode 20. A current is flowed from the electrode 20 for electrodeposition to electrodeposite the Au material partially on the conductor terminal and electrode 20 exposed from insulator layers 15 and 17, forming a connection terminal 23 for the flexible wire 24.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an inductance type or magnetoresistive type multi-channel thin film magnetic head.
In particular, it is an object of the present invention to provide a method that can easily and inexpensively connect a lead lead-out portion of a high-density recording head to a flexible wire.

Thin-film magnetic heads are manufactured using semiconductor integrated circuit manufacturing technology, so they can be easily microfabricated and the head element can be miniaturized, so they are attracting attention as magnetic heads for multichannel recording with narrow track widths. has been done.

In an inductance-type thin-film magnetic head, at least one side of the magnetic core is made of a thin-film magnetic material, as compared to a conventional monolithic magnetic head. Therefore,
This magnetic head has the following characteristics: during recording, the leakage magnetic flux distribution in the working gap is theoretically steep, it has excellent short wavelength recording characteristics, and the aforementioned narrow track is possible. , which is suitable for high-density recording.

On the other hand, magnetoresistive thin-film magnetic heads are used only for reproduction, but because they directly respond to the magnetization recorded on the recording medium, they are suitable for reproduction of high-density recorded signals, and they also provide high performance even at low speeds. It has the feature of being able to obtain output.

For these reasons, as a magnetic head for audio pulse code modulation (PCM) recording, which enables high-quality recording and playback of audio signals, an inductance-type multichannel thin-film magnetic head is used for recording, and a magnetoresistive type is used for playback. Some systems using multi-channel thin film magnetic heads have been put into practical use.

It is an object of the present invention to provide a manufacturing method for simultaneously bonding the terminal lead-out portions and flexible wire leads of these inductance type or magnetoresistive type multi-channel thin film magnetic heads. The present invention provides a method for finishing the tape sliding surface with high precision using multiple heads at the same time by clip-feed grinding.

In addition to the above-mentioned characteristics of these multi-channel thin-film magnetic heads, the head elements can be fabricated using vapor deposition and photofabrication techniques, making it possible to achieve high yields and mass simultaneous production due to uniform characteristics. However, as the number of elements increases, the pitch between the terminal lead-out portions becomes extremely dense. For example, 1/4 inch (6,351
A multi-channel thin-film magnetic head in which 32 channels of head elements are formed within a width of 20 nm) requires 64 terminal lead-out portions, and the pitch thereof is 0.1 mtn. Furthermore, there is a trend toward higher density in the future, and there is a problem in that the cost for terminal processing will be relatively high compared to other parts. In addition, in the current thin-film magnetic head, due to the electromagnetic characteristics, it is necessary to finish the tape sliding surface with high precision at a low depth of 10 to 30 ttm for gap deboosing, compared to conventional monolithic magnetic heads.
Processing becomes difficult.

First, before explaining the details of the method of the present invention, the structure of a short wavelength multi-channel thin film magnetic head suitable for high recording density will be described.

FIG. 1 shows the main components of a thin film magnetic head.

As is clear from the figure, a protective cover 4 is bonded to an element surface 2 of a substrate 1 that constitutes a thin film magnetic five-piece element.

A multi-channel actuating element is located in the joining gap 6 between the tape sliding surface 3 of the substrate 1 and the tape sliding surface 3 of the protective cover 4, and in the case of an inductance type, a pair of magnetic materials. The nonmagnetic layer sandwiched between them constitutes a recording gap, and in the case of a magnetoresistive type, a magnetic layer serving as a magnetoresistive element constitutes a reproduction gap. A conductor terminal pattern 7 for lead connection is formed on the other end of the element surface 2 of the substrate 1, and is connected to a lead portion 9 exposed at one end of the flexible wire 8 by wire bonding. . The substrate 1 and the flexible wire 8 are bonded and fixed to the helad base 1o.

FIG. 2 shows a schematic cross-sectional view of a short wavelength magnetoresistive multichannel thin film magnetic head operating element. For short wavelengths, unlike conventional magnetoresistive heads,
A structure in which magnetic shields are provided on both sides of a magnetoresistive element is common. As shown in the figure, a bias layer 1 made of a high-resistance material is placed on a magnetic substrate 1 via an insulating layer 11.
21 Magnetoresistive element made of ferromagnetic material 13. A conductor 14 for lead connection is formed. A magnetic shielding film 16 made of ferromagnetic material is formed on top of the insulating layer 15 via an insulating layer 15, and an insulating layer 17. Protected by protective cover 4.

A conventional method for manufacturing a magnetoresistive thin film magnetic head having such a structure will be described. 5i02. Mu/! An insulating film 11 such as 203 is formed, and a high resistance material such as Ti and He-F are formed thereon.
By forming a film on a ferromagnetic material such as an alloy using methods such as sputtering, electrodeposition, or vapor deposition, and etching it using photoetching technology, multiple channels can be formed as shown in Figure 3. Bias layer 12 necessary for thin film magnetic head
．． Patterns of the liaison resistance effect element 13 and the tape sliding surface processing monitor element 13' are formed. Then, from both ends of the magnetoresistive element 13 and the monitor element 13, a conductor terminal pattern 14 for lead connection made of a material with good conductivity such as MuI, Mu, Cu, etc. is formed.

After that, the magnetoresistive element 13 and the conductor terminal pattern 1
A magnetic shielding film 16 made of a ferromagnetic material such as a He-Fe alloy is formed through an insulating layer 16 made of a material such as SiO2 or K120S, which covers a part of the film 120.
3. Form an insulator layer 17 such as 5i02. Thereafter, a portion of the conductive terminal pattern 14 is exposed for each multi-channel head, and a plurality of protective covers 4 are bonded. after that,
A plurality of multi-channel thin film magnetic heads are formed on a substrate 1 and each head is cut into 0 parts.

As shown in FIG. 1, the head is adhered to the head base 1o, and the conductor terminal pattern 14 formed on the head and the glue 9 of the flexible wire 8 are aligned, and at the same time, the flexible wire 8 is attached to the head base 1o. Fix with adhesive. After that, a plurality of conductor terminal patterns 14
and the lead 9 of the flexible wire 8 are connected by wire bonding using ultrasonic waves, and after rough processing by grinding,
While measuring the resistance value of the monitor element 13', the tape sliding surface 3 was finished by lapping to complete the head.

In the above manufacturing method, since the conductor terminal pattern 14 and the lead 9 of the flexible wire 8 are connected using an ultrasonic wire bonder, in the case of a multi-channel head, there are a large number of connection points and the work efficiency is reduced. However, the strength of the joints is often low, peeling occurs frequently, and reliability is poor. As a method for connecting the conductive terminal pattern 14 and the lead of the flexible wire 8, in addition to the ultrasonic wire bonding method, the Mu-U-8N eutectic method, the solder reflow method, etc. are generally known. Considering the former Mu-8n eutectic method, the Mu-Sn eutectic method requires the Au film thickness to be at least 1.5 μm or more. In the magnetoresistive effect multi-channel thin film magnetic head for short wavelengths, as shown in FIG. 2, the distance g1. g2 is 0.5
The gap is about 1 μm. In such a case, since it is necessary to ensure insulation between the conductor terminal pattern 14 and the magnetic shielding film 16, the thickness of the conductor terminal pattern 14 cannot be greater than 1, and generally is as thick as soil of g2, so Au is used as the conductor terminal material.
Even when using the above-mentioned structure, the eutectic bonding of Au-Sn cannot be realized.

Furthermore, when considering Mu-Sn eutectic formation, the portion of the conductive terminal pattern 14 that overlaps with the lead of the flexible wire must be formed into an Au film with a thickness of 1.6 μm or more by some method. Generally, after the conductor terminal pattern 14 is formed in the manufacturing method described above and before the insulator layer 16 is formed, a thin film is applied over the entire surface to ensure good adhesion between the conductor terminal pattern material and the Au material. A material that will become the plating electrode is deposited on the entire surface, and an insulating material such as a resist is applied on top of the material to expose the joint part of the conductor terminal pattern with the flexible wire and the current terminal part for electrodeposition, and the conductor terminal pattern is formed by electrodeposition. After that, the insulating material is removed, and the plated electrode material deposited on the substrate 1 is etched to form a part of the conductor terminal pattern. Only the necessary thickness of the Au material is left for the mu-sn eutectic. Doing this will not only reduce work efficiency, but also cause the magnetoresistive element to
By depositing the hot plating electrode material and etching it again, there are drawbacks such as the surface of the magnetoresistive element being damaged during etching, resulting in deterioration of its characteristics.

In addition, in the case of soldering and reflow methods, for example, with a 32-channel multi-channel head for finch tables,
The pitch between the conductor terminals is within 0.1 mm, and the introduction of solder reflow methods such as controlling the amount of solder is not suitable due to cost, workability, and reliability.

In addition, in the rough machining of the tape sliding surface 3, a plurality of thin film heads are lined up using the end surface 19 of the head base 1o as a grinding reference, and after simultaneous clip-feed grinding, a monitor element for machining the tape sliding surface is attached to each individual head. The finishing process is performed by lapping while measuring the resistance value of the magnetic head, but since the grinding reference is the end face 19 of the head base 1o, the multi-channel thin film magnetic heads formed on the aforementioned substrate are cut into individual heads. Due to dimensional errors during grinding and finishing dimensional errors of head bases, etc., variations occur in the depth of the magnetoresistive element of each head after simultaneous grinding of multiple heads (in the case of inductance type thin film heads, gap depth). . The above-mentioned variations have to be added to the lapping process, which has the disadvantage that the efficiency of one operation is extremely poor because of the extra lapping, which is inferior in processing efficiency in several stages compared to grinding.

The present invention solves the drawbacks of the conventional methods by providing a terminal electrode for electrodes connected to the multi-channel head element at the same time as forming a multi-channel thin film magnetic head element for short wavelengths. This makes it possible to easily electrodeposit mu on a part of the conductive terminal pattern and the lead of the flexible wire using Au-8n eutectic.Furthermore, if necessary, at the same time as forming the head element, tape is applied. A method for manufacturing a thin-film magnetic head that can improve the accuracy of the depth of a magnetoresistive element or the gap depth of an inductance type during grinding by forming marks for sliding surface grinding, and that can be manufactured easily and at low cost. The purpose is to provide the following.

An embodiment of the manufacturing method of the present invention will be described below with reference to the drawings. Figure 4 shows the pattern on the substrate after forming the head element, electrodeposited terminal electrodes, and marks for grinding the tape sliding surface. FIG. 6 is a schematic cross-sectional view of the head operating element section, and FIG. 6 is a perspective view of the main part thereof.

A magnetic substrate made of ferrite material etc. whose surface is finished with a smooth surface without being twisted (N is applied to the surface of a non-magnetic substrate such as glass).
It may also be a substrate on which a magnetic layer such as e-Fe alloy is deposited, and the magnetic layer has a role of magnetic shielding.
An insulator layer 11 such as iO2, aluminum 1203, etc. is formed, and a high resistance material such as Ti is deposited using a mask in the area surrounded by the two-dot chain line in FIG. By depositing a magnetic material over the entire surface of the substrate 1 and etching it using a two-photo etching technique, the bias layer 12. required for a plurality of multi-channel thin film magnetic beds is formed. lii resistance effect element 13-p sliding surface processing monitor element 13';
Terminal electrode for electrodeposition 20. and tape sliding surface grinding marks 21 are simultaneously formed. The terminal electrode 2o for electrodeposition is attached to the substrate 1
By providing it on the outer periphery of the surface of the substrate, it is possible to make the current density uniform throughout the substrate during electrodeposition. Here, the tape sliding surface grinding process marks 21 are formed at both ends of the multi-channel head element array at positions that can be observed during the tape sliding surface grinding process. After that, one end of the magnetoresistive element 13 and the monitor element 13' is connected to the electrodeposition terminal electrode 2o, so that one end can be directly connected to the electrodeposition terminal electrode 2o.
A conductor terminal pattern 14 for lead connection is formed of a material with good conductivity such as copper or copper. Of course, when forming the conductor terminal pattern 14, the terminal electrode 2o for electrodeposition and the tape sliding surface grinding mark 21 may be formed at the same time, but the tape sliding surface grinding mark 21 and the magnetoresistive element 13
The accuracy of the distance a from the end of the magnetoresistive element 13 and the conductive terminal pattern 14 deteriorates due to misalignment between the magnetoresistive element 13 and the conductive terminal pattern 14.

Next, 8i02 covers the magnetoresistive element 13, the monitor element 13', and part of the conductor terminal pattern 14. am 120s
A magnetic shielding film 16 made of a ferromagnetic material such as a NeJ-Fe alloy is formed on an insulating layer 16 made of a material such as, and an insulating layer 1 made of a material such as Mu12os or 5i02 is further formed thereon.
form 7. After that, a stain flow is passed through the electrodeposition terminal electrode 2o, and the Au material is electrically applied to the conductor terminal exposed from the insulating layer 16, 17 and a part of the electrodeposition terminal electrode 2o to a thickness of 1.6 or more. Connecting terminal 23 with flexible wire
form. This electrodeposition step may be performed after any step from the time the electrodeposition terminal electrode 2o is formed to the step of cutting each head. Next, a plurality of protective covers 4 are glued so that the connection terminals 23 and tape sliding surface grinding marks 20 are exposed, and the ζ turns 14 of the conductor terminals are attached at the portions indicated by dashed lines in FIG. At the same time as separating the terminal electrodes 22 for electrodeposition, a plurality of multi-channel thin film magnetic heads formed on the substrate 1 are cut and separated one by one for each head.
They are glued to the head base 10. Next, as shown in FIG. 6, the connection terminals 23 formed on the head are aligned with a large number of leads 26 in which Sn is attached to Cu protruding from the tip of the flexible wire 24, and the head base 10 is attached. After fixing.

Heat and press the seat tool onto the top of the lead 24, and then
Connected by Sn eutectic. Thereafter, a plurality of thin film magnetic heads are set on this table so that the tape sliding surface grinding marks 21 are at a fixed position above the table surface of the grinder, and the heads are ground by clip feeding. Next, while measuring the resistance value of the monitor element 13' for each head, the tape sliding surface is finished by lapping until the resistance value reaches a constant value, thereby completing the head.

As explained above, according to the method of the present invention, in a multi-channel thin film magnetic head for short wavelengths, the head operating element portion and the terminal electrode for electrodeposition are formed on the insulator in the same process so as to be connected to each other, and AU by protecting a part of the element with an insulator
Since the material is electrodeposited, connection terminals for connecting flexible wires can be easily formed on part of the conductor terminal pattern. Muro-8n eutectic bonding becomes possible, and a large number of multi-channel connections can be made at once, improving work efficiency. In addition, the connection strength is several times stronger than that of ultrasonic wirebond connections, improving reliability.

By configuring the multi-channel thin film head so that one side of the conductor terminal pattern for each channel is electrically connected to the electrodeposition terminal electrode and the other side is not directly connected to the electrodeposition terminal electrode, the head operating element for each channel is Although it is composed of a plurality of stacked layers, the quality of the connection can be easily determined by looking at the electrodeposition state after the electrodeposition process.

Electrodeposition cannot be performed on the conductor terminal pattern that is not directly connected to the electrodeposition terminal electrode of the head with a poor connection. Since post-processing can be omitted for defective heads, material costs and man-hours can be reduced.

As described above, the present invention can provide a method for manufacturing a thin film magnetic head that can easily connect the conductor terminal pattern of a multichannel thin film magnetic head and a flexible wire at low cost.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a main part of a conventional example of a thin-film magnetic head, FIG. 2 is an enlarged sectional view of the main part, and FIG. 3 shows a pattern after a plurality of head operating elements are formed on a conventional substrate. It is a diagram. FIG. 4 is a diagram showing a pattern after a plurality of head elements are formed on a substrate in an embodiment of the method for manufacturing a multi-channel thin film magnetic head according to the present invention, and FIG. 6 is an enlarged cross-sectional view of the main parts thereof. FIG. 6 is a perspective view of essential parts showing an example of the obtained thin film magnetic head. 1...Magnetic substrate% 11.16.17...
... Insulator layer, 12 ... Bias layer, 13.
...Magnetoresistive effect element, 13'...Monitor element for tape sliding surface processing, 14...Conductor terminal pattern, 2o...Terminal electrode for electrodeposition, 21・
... Tape sliding surface grinding mark. Name of agent: Patent attorney Toshio Nakao and 1 other person No. 1
Figure θ Figure 2 Figure 3 Figure 4 Δ Figure 5 Figure 6? 4

Claims (1)

[Claims] (1) A step of forming terminal electrodes for electrodeposition each connected to a plurality of head element sections, and a step of electrodepositing a mu-U terminal on a part of the conductive terminal pattern of the head element section. , a step of cutting the conductor terminal pattern to separate the head element portion into each channel, a step of connecting a flexible wire lead and the mu U terminal, and a tape sliding surface processing step. A method for manufacturing a multi-channel thin film magnetic head characterized by: 2) A method for manufacturing a multi-channel thin film magnetic head according to claim 1, characterized in that a tape sliding surface grinding mark is formed at the same time as forming a terminal electrode for electrodeposition. (3) Manufacture of a multi-channel thin film magnetic head according to claim 1, characterized in that a tape sliding surface grinding mark and a magnetoresistive element are formed at the same time as forming the electrodeposited terminal electrode. Method. -) When forming a terminal electrode for electrodeposition, a magnetoresistive element is formed at the same time, and when forming a conductive terminal pattern of the head element part, only one conductive terminal pattern of the magnetoresistive element is formed for electrodeposition at the same time. The conductor terminal pattern is connected to the terminal electrode, and the other conductor terminal pattern is not directly connected to the electrode terminal electrode.