JPH05266450A - Magnetic head assembly - Google Patents

Abstract

PURPOSE:To lessen the generation of defects at the time of assembling a magnetic disk device and to enhance the reliability of the device by positioning a tube in a part of the magnetic head assembly and adhering wires to a resin block in the tube. CONSTITUTION:Tensile force acts on the wires 12 of the magnetic head assembly in order to align and shape the wires at the time of assembly of the magnetic head assembly. The tube 13 is held in a load arm 14 by a retainer 16b. The tube 13 is deformed by the retainer 16b and the wires 12 are compressed to the tube wall and are hardly movable. The wires 12 exist in the deformed part of the tube 13 and are prevented from moving by being held in the resin block 17 in the tube. In addition, the wires 12 and the remaining part of the tube 13 are free and, therefore, the wires and the tube maintain flexibility. The resin block 13 is formed by packing a resin soln. wetting the wires in the tube and evaporating the solvent to solidify the resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic head assembly, and more particularly to a structure of a magnetic head assembly having an improved wiring structure for connecting a magnetic head and a circuit board.

[0002]

2. Description of the Related Art In a magnetic head assembly mounted on a magnetic disk device, a wire for transmitting a signal from or to the magnetic head is routed through a tube mounted on a load arm to a circuit board. .. The tube is held by tube retainers at the front, center and rear ends of the load arm. Since the tube is deformed by these tube retainers and the wire inside is pressed, the wire does not slide in the tube even if it is pulled by a slight force, for example, about 5 to 15 gf.

Generally, a large-capacity magnetic disk device employs a structure in which a plurality of magnetic heads are incorporated and the wires from the magnetic heads are collected and directly wired to a circuit board. In the assembling work in such a case, it is necessary to arrange a large number of wires so as not to be entangled with each other before wiring. Therefore, the work of shaping or aligning the wires becomes complicated, and a pulling force is applied to the wires, the wires are pulled and move in the tube, and it is unavoidable that a force is applied to the tip of the wires. Even when paying close attention during the assembly work, the wire is pulled and the wire shape at the tip of the magnetic head collapses, causing a problem in the flying posture of the magnetic head,
Further, it causes defects such as bending of the gimbal to which the magnetic head slider is attached.

In order to solve this problem, Japanese Patent Laid-Open No. 3-5
In the 2109 publication, a heat shrink tube is used to adhere the tube to the wire and prevent the wire from sliding within the tube.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention
In the publication, the wire from the head is inserted into a heat-shrinkable tube and heat-treated to shrink the tube and bring it into close contact with the wire, so that the wire does not easily slip in the tube. This method is effective for the purpose of preventing the wire from slipping. However, heat shrink tubing generally contains large amounts of plastic. Therefore, since a large amount of the plastic material is volatilized by the heat treatment, it is inevitable that the tube is hardened, that is, the rigidity is increased as a result. Further, since the tube and the wire are substantially integrated over the entire length of the tube, the thin wire tends to be harder against bending than a state in which the thin wires are individually assembled. The stiffening of the tube or the composite of the tube and the wire means that the tube has a greater influence on the levitation load, and therefore, the hardness control or the adjustment of the levitation characteristic of each magnetic disk device becomes more strict. The need arises. Furthermore, the length of the tube also changes with contraction. Since the dimension of the heat-shrinkable tube after shrinking is slightly unstable, strict control of the assembly dimension and the physical properties of the parts used is essential to maintain the floating characteristics required for the magnetic head.

It is an object of the present invention to make a wire of a magnetic head assembly harder than a tube of the magnetic head assembly so that the wire does not easily slip with respect to the tube, so that a magnetic head having a small number of defects during the assembly work of the magnetic disk device is highly reliable. To provide an assembly.

[0007]

In order to achieve the above object, the present invention provides a magnetic head assembly in which a wire drawn from a magnetic head is inserted into a tube and wired, and the tube is located at a part of the magnetic head assembly. Then, it has a resin block arranged in the tube, and the wire is bonded to this resin block.

[0008]

The wire is bonded to the resin block located in a part of the tube and disposed inside the tube, and when the wire is pulled, the tube is bonded to the resin block, or the tube and the resin block are rubbed, Alternatively, since the deformed or bent portion of the tube interferes with the movement of the resin block and resists the sliding of the wire, the tube is made of a material whose surface is not wet like Teflon (trade name). However, the wire does not move. Further, since the remaining portions of the tube and the wire are free, the flexibility of the wire and the tube is not impaired.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the magnetic head assembly of the present invention will be described below with reference to the drawings.

FIG. 1 is an external view of a carriage assembly in a magnetic disk device having a magnetic head assembly according to the present invention. The magnetic head assembly 1 is attached to the head arm 2 and constitutes a carriage assembly together with the printed circuit board 3 and others. The tube 13 extending from each magnetic head assembly 1 is loosely fixed to the end of the printed circuit board 3. The wire 12 held in each tube 13 is drawn out to the wiring side of the printed board 3 and aligned on the pad 31, and then wired.

FIG. 2 is a diagram showing the external appearance of the magnetic head assembly in detail. The wire 12 for transmitting the signal of the coil attached to the core slider 11 is inserted into the tube 13 and attached to the load arm 14. The tube 13 is a tube retainer 1 at the tip of the load arm 14.
6a, the tube retainers 16c and 16d at the rear ends, and the tube retainer 16b located between them, and held by the load arm 14.

The tube 13 includes tube retainers 16a-16
It is held and deformed by d and the load arm 14, and the wires 12 are closely packed. In this magnetic head assembly, the resin block has the wires 12 closely packed and the tube 1
3 is located in the deformed portion and is inside the tube, and the wire 12 is held by this resin block. explain in detail.

FIG. 3 shows a cross section of the tube in the tube retainer 16b, for example. The magnetic head assembly is
When assembling this, the wire 12 is shaped by tweezers or the like for alignment and shaping. At that time, a tensile force of, for example, about 10 to 20 gf is applied to the wire 12 by force. On the other hand, the tube 13 is held by the load arm 14 by the tube retainer 16b.
The tube 13 is deformed by the tube retainer, and the wire 12 is pressed against the deformed tube wall to make it difficult to move. As a result, even if a tensile force of about 5 to 15 gf is applied to the wire 12, it does not slide with respect to the tube 13. However, when the carriage assembly is assembled, a force of 10 to 20 gf may be applied to the wire 12, so that the wire 12 may be pulled and slip, and a force may be applied to the tip of the wire 12 in some cases. When such a situation occurs, the shape of the wire at the tip of the magnetic head may collapse, causing a problem in the flying posture of the magnetic head. At times, a defective accident occurs in which the gimbal 15 that supports the core slider 11 is deformed.

In this magnetic head assembly, since the wire 12 is held by the resin block 17 disposed inside the tube 13 at the deformed portion of the tube 13 as described above, the wire 12 is pulled. At this time, the adhesion between the tube 13 and the resin block 17, the friction between the tube 13 and the resin block 17, or the deformed or bent portion of the tube 13 hinders the movement of the resin block 17, 1
2 is not moved, and the wire 12 and the tube 1 are not moved.
Since the remaining portion of 3 is free, the flexibility of the wire 12 and the tube 13 is not impaired.

The resin block 13 is formed, for example, by filling a tube with a resin solution capable of wetting at least the wire surface and then volatilizing the solvent to solidify the resin. In the portion of the tube 13 where the tube retainer 16 is pressed, the wires 12 are almost in close contact with each other, so that the resin solution easily fills the voids by the surface tension, and after the solvent volatilizes, the wire 1 in that portion.
The voids between the two are filled with the solidified resin 17 and are bonded and integrated with each other. On the other hand, in the wire 12 in the portion where the tube retainer 16 is not pressed, the resin adheres to the wire surface, but
The two are not glued together. Therefore, the wire 12 at that portion is simply attached with a thin film of resin, and the flexibility is hardly impaired. However, the portion of the wire 12 that is integrated with the resin block 17 is hard and difficult to bend, and the tube 13 at that portion is deformed or bent. Therefore, even if a tensile force is applied to the wire 12, the deformed or bent portion Disturbed by slipping.

The resin constituting the resin block 17 is preferably one that is easy to handle, has good environment resistance, and has flexibility after curing, and must be one that can be dissolved in a solvent. For example, polyvinyl butyral, nylon varnish, acrylic resin, etc. are suitable. Usually, the tube 13 is often Teflon (trade name), and in that case, the surface of the Teflon is extremely inactive, so that the resin solution cannot wet the surface of the tube, so that the resin is not transferred to the tube 13. It does not adhere.
Therefore, the resin solution wets the surface of the wire 12, and particularly in the portions where the wires 12 are pressed against each other and are in close contact with each other, the resin solution fills the voids due to the surface tension. On the other hand, in most places that are not in close contact with each other, the surface of the wire 12 is wet, but the resin solution hardly adheres across the wires. After being left in this state to evaporate the solvent, the pressed portion of the wire 12 is adhered by the resin filled between the wires to form a resin block 17 having a relatively large diameter. By integrating the wire 12 and the resin block 17 in this way, the block 17 has increased strength and becomes harder against bending, that is, rigidity becomes larger. However, in other parts, although the resin thin film is adhered on each wire, the thin film is not thin enough and multiple wires are not adhered to each other. Can be ignored.

In the portion of the tube 13 where the tube retainer 16 is pressed, the tube 13 is also deformed and bent, so that there is no room for the resin block 17 to slide in the deformed portion. The wire 12 does not move even when the pulling force is applied, so that the force is not applied to the tip of the wire. In order to increase the slip resistance of the tube, it is effective to form a plurality of bent portions on the tube 12 as shown in FIG. 6, for example. Further, since the tube 13 and the wire 12 are hardly hardened in the portion of the tube 13 where the tube retainer 16 is not pressed,
The flexibility is not compromised and the hardness is easily managed.

FIG. 4 shows a process of forming a resin block on the tube 13. Polyvinyl butyral, nylon varnish, acrylic resin and other suitable solvents,
For example, a resin solution 5 dissolved in alcohol, acetone, freon or the like is prepared. Depending on the case, the concentration of the resin solution 5 is selected from the range of about 0.5 to 10%. The tip of the tube 13 of the assembled magnetic head assembly 1 is immersed in the resin solution for 1 to 5 seconds. The resin solution 5 is
It is sucked up into the tube 13 due to the capillary phenomenon and rises up to the vicinity of the tube retainer 16. For example, a self-fusing wire varnish dissolved in ethyl alcohol has a concentration of 5 w
If t% resin solution is used, tube inner diameter 0.23m
In the case of immersion for 1 second, the resin solution 5 is 20 to 30 m.
It is sucked up to a height of about m. After evaporating the solvent in this state, the wire can withstand a tensile force of 30 to 50 gf. The resin solution sucked up into the tube by the above treatment becomes about 0.05 mg in terms of the amount of resin. Since the amount of the resin used is such a small amount, the wire 12 is hardly hardened by the resin adhering to the surface except the pressed portion. The means for filling the resin solution 5 into the tube 13 is not limited to the above, and the resin solution 5 may be attached to the end of the tube 13 by a spoid or the like.
It can also be achieved by dropping.

When the number of wires 12 passing through the tube 13 is large, the resin concentration may be low, but when the number of wires 12 is small, the block 1 solidified with resin is used.
In order to increase the diameter of 7, it is necessary to increase the resin concentration. In particular, when the diameter of the wires 12 is large, the voids between the wires also become large, and it is necessary to increase the concentration of the resin solution to the extent that voids do not form as the solvent volatilizes. Further, the stronger the bending of the portion pressing the tube 13, the more difficult it becomes for the resin block 17 to slide and move inside the tube 13, and the greater the effect of countering the tensile force.

FIG. 5 shows another method of forming the resin block 17 on the tube 13. The figure shows a cross section of a wire. This wire consists of a wire 12 having an insulating coating 22 applied to a core wire 21 and a varnish 23 which is melted by heat or an organic solvent and solidified and adheres when the wire is removed (this wire will be referred to as self-fusion hereinafter). Called sex wire). The magnetic head assembly 1 is assembled in the same manner as the above method using the self-bonding wire as the wire 12 for transmitting the signal of the coil. In place of the resin solution 5 in FIG. 4, an organic solvent 5 capable of dissolving the varnish is used,
The tube 13 is filled with the organic solvent 5 by the same operation. The organic solvent 5 is the varnish 23 on the surface of the wire 12.
And the organic solvent 5 is volatilized, and the varnish 2 is applied to the portion of the tube 13 where the tube retainer 16 is pressed.
The block 17 of 3 is formed and the wire 12 is adhered to this resin block. In this way, the same effect as the above case can be obtained.

In these cases, in the magnetic head assembly 1 using only the components that are not affected by the organic solvent 5, this solvent can be used for cleaning the magnetic head assembly 1, and the magnetic head assembly 1 can be used. By immersing the whole in the cleaning liquid, it is possible to perform cleaning and automatically fill the tube with the organic solvent 5.

In the above description, it is assumed that a resin solution is used as the resin for bonding and solidifying the wire. However, this does not mean that only the resin dissolved in a solvent is effective. For example, a low molecular weight organic compound that can be solidified and adhered by polymerization may be used.

[0023]

According to the present invention, the wire is prevented from slipping relative to the tube without losing the flexibility of the wire and the tube, and the pulling force applied to the wire is not applied to the tip of the wire. Therefore, it is possible to obtain a magnetic head assembly that is less likely to cause defects during the assembly work of the magnetic disk device.

[Brief description of drawings]

FIG. 1 is a perspective view showing an example of a carriage assembly in a magnetic disk device.

FIG. 2 is a perspective view showing an embodiment of a magnetic head assembly of the present invention.

FIG. 3 is an enlarged sectional view of a tube in a certain tube retainer in FIG.

FIG. 4 is an explanatory diagram showing a method of forming a resin block on a tube.

FIG. 5 is an enlarged cross-sectional view of a wire used in another method of forming a resin block on a tube.

FIG. 6 is an explanatory diagram showing another relationship with the tube in the tube retainer.

[Explanation of symbols]

 1 ... Magnetic head assembly 2 ... Head arm 3 ... Circuit board 12 ... Wire 13 ... Tube 14 ... Road arm 17 ... Resin block

Claims (1)

[Claims] 1. A magnetic head assembly in which a wire drawn out from a magnetic head is inserted into a tube and wired, wherein the tube has a resin block located in a part of the tube, and the wire has a resin block. A magnetic head assembly characterized by being bonded to a resin block.