JPH09282625A - Lead wire for hdd magnetic disk - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a flexible lead wire by composing the lead wire from a signal wire holding section which holds the signal wire constituted from metallic fine wires by plastic film and a signal wire exposed section having the signal wire exposed. SOLUTION: A signal wire holding section 3 is formed while the insulation between signal wires is held by the process that a specified section of four signal wires each composed of copper wires juxtaposed with an interval of 50μm is subjected to thermocompression bonding with the PET films 5 which has a length corresponding to the suspension and a heat-sensitive adhesive layer 8 of 15μm length. This process is repeated with a specified interval of length. By continuously operating this process, bare signal wire sections 4 and signal wire sandwiched sections 3 are alternately formed. This composition is cut with an arbitrary size to obtain lead wires 1 for HDD magnetic head.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head of a hard disk drive (hereinafter referred to as HDD) and a flexible printed circuit board (hereinafter referred to as FPC) of a signal conversion circuit terminal.
The present invention relates to a lead wire for an HDD magnetic head used for a signal wiring between them.

[0002]

2. Description of the Related Art Conventionally, a signal wire of a HDD magnetic head lead wire 1A for connecting a magnetic head of a hard disk drive and an FPC of a signal conversion circuit terminal is, for example, an ultrafine wire made of copper wire and polyurethane. An enamel wire provided with an insulating film has been generally used. A plurality of signal lines made of this enamel wire are used by being inserted into a plastic tube 11 having a small diameter as shown in FIG. 6 for protection when being fixed to the suspension 10 as shown in FIG. Was there. The plastic tube 11 and the signal line 2 are UV injected into the tube.
The resin 12 was hardened and fixed. Also, the signal line 2
Since the terminal of (1) is bonded to the magnetic head by ultrasonic bonding, the film peeling portion 13 is formed on the signal line 2 by peeling the insulating coating of the bonding portion by the excimer laser.

On the other hand, various lead wires 1A for HDD magnetic heads which do not use ultrafine metal wires for the signal line 2 have been studied. For example, the signal line 2 is formed by directly printing on the suspension 10 by vapor deposition or the like, or the FPC. Attempts have also been made to adopt. However, in the case of these lead wires, there are many technical and facility problems to be solved when joining the signal line and the magnetic head, and
The lead wire obtained is expensive and has not been popularized.

In recent years, as HDDs have become smaller and larger in capacity, there has been an increasing demand for smaller and lighter HDD magnetic head lead wires. Specifically, miniaturization of magnetic heads has progressed, and miniaturization of a head flying mechanism (not shown) called a slider (not shown) has become remarkable. As a result, the diameters of the signal line 2 and the plastic tube 11 which have been conventionally used have been simultaneously reduced.

[0005]

In order to dispose the HDD magnetic head lead wire 1A on the suspension 10, a caulking portion 14 is provided on a part of the suspension 10 as shown in FIG. 7, and the caulking portion 14 is provided. A general method is to crimp and hold the HDD magnetic head lead wire 1 with 14, and this method requires a step of covering the lead wire 1A with a fluorine-based resin tube 11 in order to protect the signal wire 2. However, since it is extremely difficult to mechanize the step of covering the lead wire 1A with the fluororesin tube 11,
Although the worker manually covers the lead wire 1A with the fluororesin tube 11 by hand, there is a problem in workability such that the signal wire 2 is easily broken. This work has become more difficult as the diameter of the signal line 2 is reduced.

Further, although the tube 11 is mechanically caulked and fixed on an arm called a suspension 10 for vertically moving the magnetic head in order to hold the HDD magnetic head lead wire 1A, the suspension 10 and the tube 11 are fixed. In addition to the distortion easily occurring in the caulking portion 14, the rigidity of the tube 11 adversely affects the vertical movement of the suspension 10.

Further, since the plurality of signal lines 2 constituting the lead wire 1A are twisted or inserted in the tube 11 in a state of being arranged in parallel, it is necessary to maintain insulation between the signal lines. As the signal line 2, an insulated electric wire such as an enamel wire in which a polyurethane insulation film is applied to a copper wire is used. However, in order to connect the magnetic head and the signal line 2 by ultrasonic bonding, a step of peeling the insulating film at the bonding portion with an excimer laser is necessary. However, even if it is attempted to peel off the ultrafine wire insulating film with an excimer laser, it is difficult to remove the insulating film with high precision, and it is difficult to control the excimer laser.

On the other hand, the lead wire 1A formed by the printing method or the FPC described above has many features such as excellent mass productivity as the lead wire 1A for the HDD magnetic head, small size and light weight, and integration with the suspension 10. Have. However, in order to join the lead wire by the printing method or the FPC and the FPC on the side of the magnetic head or the signal conversion circuit terminal, the pad shape of the bonder and the head is reviewed and joined in order to make the joining simple and reliable. It was necessary to study new technologies that were not available in the conventional process, such as establishing a strong non-destructive inspection line, and the spread of these technologies was delayed.

An object of the present invention is to provide an inexpensive lead for an HDD magnetic head, which has excellent characteristics of a printing method and an FPC type lead wire in terms of characteristics and functions, and can be easily joined to a magnetic head by bonding. It is to provide a line.

[0010]

Means for Solving the Problems A plurality of thin metal wires made of copper or copper alloy are used as signal lines, and the signal lines are two plastic films with an adhesive layer, or one plastic film with an adhesive layer and one film. The signal line sandwiching portion 3 sandwiched by the plastic film having no adhesive layer and the signal line exposing portion 4 exposing the signal line 2 are alternately formed at predetermined intervals.

The signal line exposed portions 4 may be formed by sandwiching the signal lines with a short plastic film at a constant interval, and the signal line exposed portions 4 may be formed by forming through holes in each of the plastic films. May be formed.

Further, a part of the signal line may be wired in an arbitrary shape so as to correspond to the wiring shape, and may be sandwiched by a plastic film, or these lead wires may be bent into an appropriate shape.

[0013]

Since the signal wire made of a thin metal wire is sandwiched between the plastic films, the lead wire can be reduced in weight and thickness, and a flexible lead wire can be obtained. In addition, the lead wire can be bent, and it can be tightly joined to the suspension by simple means such as providing an adhesive layer on the suspension joint surface side. The movement is not disturbed.

Further, since it is not necessary to give insulation to the signal line itself and the exposed portion of the signal line is provided, the step of exfoliating the insulating film by the excimer laser, which is conventionally required for bonding and joining, becomes unnecessary. The cost can be reduced by drastically reducing man-hours, and an inexpensive lead wire can be obtained.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the drawings. Example 1 As shown in the plan view of FIG. 1A, predetermined portions of four signal lines 2 made of copper wires having a wire diameter of 25 μm arranged in parallel at intervals of 50 μm corresponded to suspensions. P with a length of 6 μm and a heat-sensitive adhesive layer 8 of 15 μm
The ET films 5 and 5 (a cross-sectional view is shown in FIG. 2B) are thermocompression-bonded from above and below, and the signal lines 2 are sandwiched between the PET films 5 and 5 while maintaining insulation between the signal lines. The signal line sandwiching portion 3 is formed. Similarly, the signal line 2
Are sandwiched between the PET films 5 and 5 having the same heat-sensitive adhesive layer at a predetermined interval. By continuously performing this step, the signal line exposed portion 4 where the signal line 2 is exposed and the signal line 2 are exposed to P
Signal line holding part 3 held by ET films 5 and 5
Are formed alternately. Next, this is cut to an arbitrary size, and as shown in the figure, the main portion is sandwiched between the films 5 and 5, and only the portion that becomes the joint with the magnetic head or the like is exposed, and the lead wire for the HDD magnetic head. Got 1.

Example 2 Similar to Example 1, 6 μm having an adhesive layer 8 of 30 μm in thickness at a predetermined portion of four signal lines 2 made of copper wires having a diameter of 25 μm arranged in parallel at intervals of 50 μm. Of the PET sheet 5 and the adhesive layer 8 of the PET sheet 5
A PET sheet 6 having a thickness of 6 μm as shown in the sectional view of FIG. 1C is bonded to the side by pressure bonding. Then, similar to the first embodiment, a predetermined interval is provided, and the signal line exposed portion 4 in which the signal line 2 is exposed and the signal line sandwiching portion 3 in which the signal line 2 is sandwiched by the PET films 5 and 6 are alternately formed. . The HDD magnetic head lead wire 1 having the same shape as that of Example 1 was obtained by cutting this into arbitrary dimensions. In the case of the lead wire 1 of the second embodiment, thermocompression bonding is unnecessary because heat-sensitive adhesion is not performed.

Example 3 is characterized in that each of the plastic films 5, 5 and 6 used in Examples 1 and 2 is provided with a through hole 7 as shown in FIG. 2 (a). It is a thing. Then, as in the case of the first or second embodiment,
The signal line 2 is sandwiched by the plastic films 5, 5 or 5, 6 and the through holes 7 of the plastic films 5, 5 or 5, 6 are aligned at this time. Then, by cutting this into an arbitrary size,
A lead wire 1 having a plan view shown in FIG. A cross-sectional view of the obtained lead wire 1 is shown in FIGS. 2 (c) and 2 (d), respectively.

Example 4 A 6 μm PET film 5 having a 12 μm heat-sensitive adhesive layer 8 was laminated on the surface of the heat-sensitive adhesive layer 8 to form a 3 μm adhesive layer 8.
The signal line 2 having a wire diameter of 25 μm is arranged in an arbitrary shape on the PET film 5A provided with A. Further, a PET film 5 of 6 μm or a PET film of 6 μm having a heat-sensitive adhesive layer 8 of 12 μm on the adhesive layer 8A side of the PET film 5A.
As shown in FIG.
A lead wire 1 as shown in (a) was obtained. The cross-sectional views of the obtained lead wire 1 are shown in FIGS. 3 (b) and 3 (c), respectively.

Example 5 The lead wire 1 obtained in Example 1, Example 2, Example 3 and Example 4 was bent and formed into an arbitrary shape corresponding to the wiring shape, and a lead as shown in FIG. 4 was obtained. I got line 1. Since the lead wire 1 is formed without damaging the signal line 2 and in a state of being kept parallel or in a wiring state, the wiring direction can be changed by changing the direction of the signal line 2 or corresponding to the wiring inside the device. Is possible.

Example 6 Each Example 1, 2, 3, 4, 5 was used alone or in combination, and an adhesive layer was provided on the suspension joint surface side to obtain a lead wire 1 as shown in FIG. The drawing shows a state in which the HDD magnetic head is specifically arranged on the suspension 10, but the HDD magnetic head lead wire 1 of the present invention is thin and highly flexible, and has a high degree of freedom in wiring. Can be increased.

[0021]

Since the lead wire for the HDD magnetic head of the present invention is composed of the signal wire holding portion in which the signal wire made of the metal thin wire is held by the plastic film and the signal wire exposed portion in which the signal wire is exposed, We have obtained lead wires that are both lighter and thinner and have flexibility. Also,
In addition to being able to closely adhere to the suspension by a simple means of providing an adhesive layer on the suspension joint surface side, it can be bent to accommodate various wiring shapes, increasing the flexibility of wiring and increasing the flexibility of suspension design. As a result, the strain that has been conventionally caused by disposing the lead wire in the suspension is significantly reduced, and
Distortion no longer has an adverse effect and suspension movement is no longer hindered. In addition, since it is not necessary to provide insulation to the signal line itself, the insulating film peeling process by the excimer laser, which was required when bonding and joining the lead wires, is not required, and the cost can be reduced by a large reduction in man-hours and the HDD magnetic The lead wire for the head was obtained.
In addition, the thickness of the lead wire can be reduced compared to conventional lead wires using plastic tubes.
It became possible to downsize D. There are practical effects such as.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing an embodiment of a HDD magnetic head lead wire according to the present invention, in which FIG.
9B and 9C are cross-sectional views taken along the line AA of FIG.

2A and 2B are explanatory views showing another embodiment of the HDD magnetic head lead wire according to the present invention, wherein FIG. 2A is an illustration showing a manufacturing method, and FIG. 2B is a plan view of the lead wire. The figures, (c) and (d) are cross-sectional views taken along the line BB in (b) of the figure.

3A and 3B are explanatory views showing another embodiment of the HDD magnetic head lead wire according to the present invention, in which FIG. 3A is a plan view thereof, and FIGS. ) CC
It is sectional drawing in a line.

FIG. 4 is an explanatory view showing still another embodiment of the HDD magnetic head lead wire according to the present invention.

FIG. 5 is an explanatory diagram showing a specific example in which a HDD magnetic head lead wire according to the present invention is wired.

FIG. 6 is an explanatory diagram showing a configuration of a conventional HDD magnetic head lead wire.

FIG. 7 is an explanatory diagram showing a specific example in which lead wires for a conventional HDD magnetic head are wired.

[Explanation of symbols]

 1,1A HDD magnetic head lead wire 2 Signal wire 3 Signal wire sandwiching portion 4 Signal wire exposed portion 5,5A Plastic film with heat-sensitive adhesive layer 6 Plastic film without heat-sensitive adhesive layer 7 Through hole 8 Heat-sensitive adhesive layer 8A Adhesive layer 10 Suspension 11 Fluorine tube 12 UV resin 13 Film peeling part 14 Caulking part

Claims (5)

[Claims] 1. A lead wire for an HDD magnetic head, comprising a plurality of thin metal wires made of copper or a copper alloy as signal lines, wherein the HDD magnetic head lead wire 1 includes two plastic films with an adhesive layer. 5, 5 or one plastic film 5 with an adhesive layer and one non-adhesive plastic film 6 sandwiches the signal line 2, and the signal line exposed portion 4 exposes the signal line 2. A lead wire for an HDD magnetic head, characterized in that and are alternately formed at a predetermined interval. 2. The lead wire for an HDD magnetic head according to claim 1, wherein the signal line holding portion 3 is formed of short plastic films 5, 5 or 5, 6 at regular intervals. 3. The HDD according to claim 1, wherein a through hole 7 is provided in a predetermined portion of the plastic film 5, 5 or 5, 6 and the signal line 2 is exposed through the through hole 7. Lead wire for magnetic head. 4. The HDD according to claim 1, wherein a part of the signal line 2 is wired in an arbitrary shape.
Lead wire for magnetic head. 5. The HDD magnetic according to claim 1, 2, 3 or 4, wherein the signal line 2 is sandwiched between two plastic films 5, 5 or 5, 6 and bent into an arbitrary shape. Lead wire for head.