JP2002237018A - Suspension and head gimbals assembly - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a suspension capable of more effectively radiating heat from an IC chip, and an HGA. SOLUTION: The suspension is provided with a magnetic head slider having at least one thin-film magnetic head element, an elastic stainless steel flexure having the magnetic head slider secured thereto, a stainless steel load beam for supporting the flexure and applying a specified load to the magnetic head slider, an IC chip having a circuit mounted thereon for the thin-film magnetic head element, a wiring member directly formed on the flexure to mount the IC chip thereon, and a high thermal conductivity member having thermal conductivity higher than that of stainless steel, which is secured to the backside of the flexure in an area including at least the portion where the IC chip is mounted. The load beam has a through-hole, and the high thermal conductivity member is inserted into the through-hole.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a suspension for mounting an IC chip for a thin-film magnetic head element used for, for example, a magnetic disk drive (HDD) and a head gimbal assembly (HGA) provided with the suspension. .

[0002]

2. Description of the Related Art In an HDD, a magnetic head slider attached to the tip of a suspension is levitated from the surface of a rotating magnetic disk. In this state, the magnetic disk slider is mounted on a thin-film magnetic head element mounted on the magnetic head slider. And / or reproduction from the magnetic disk.

[0003] With the recent increase in capacity and recording density of HDDs, the recording frequency has been increasing. One of the means for realizing this has been proposed for magnetic head elements. This is a structure (a chip-on-suspension structure) in which a part of the drive circuit is formed into an IC chip and mounted on a suspension. By adopting this structure, the wiring distance from the drive circuit to the magnetic head element is shortened, so that unnecessary noise added to the head drive signal can be reduced, and as a result, the recording characteristics in the high frequency region are improved. I do. In addition, the magnetoresistance effect (M
R) A weak signal output from the read head element can be amplified closer to the MR head element.

[0004]

The size of an IC chip used in such a chip-on-suspension structure must be very small due to its mounting structure. However, when the size is reduced, the surface area is reduced accordingly. The heat dissipation is quite poor. Also, since it must be mounted on a suspension with a small space, and 500 MHz
In a near high-frequency region, the capacitance of the lead frame which becomes a terminal when packaged becomes noise and adversely affects the electrical characteristics. Therefore, the IC chip needs to be a bare chip. For this reason, the heat radiation of the IC chip deteriorates, and the chip temperature rises. In addition, since an extremely large current flows through the IC chip during recording, heat generation becomes extremely large, so that insufficient heat dissipation is a serious problem.

A spring member of the suspension is usually a leaf spring made of stainless steel. However, this stainless steel has a low thermal conductivity as a metal material and is very thin, so that it has a chip-on-suspension structure. In that case, cooling by heat radiation cannot be expected so much.

As described above, the conventional HGA having the chip-on-suspension structure has the following problems. (1) Since the IC chip is very thin and small, its surface area is small, and it is difficult to effectively take measures against heat generation. The stainless steel used as a material has low thermal conductivity and is very thin, so that sufficient heat cannot be dissipated by the ordinary chip-on-suspension structure. (3) The IC chip is mounted on the suspension on the side facing the magnetic medium. Therefore, I
There is a problem that it is difficult to directly attach the heat radiation structure to the C chip itself.

When the temperature of the IC chip becomes high due to heat generation and almost no heat dissipation, not only the operation of the IC becomes unstable but also the suspension may be thermally deformed.

Accordingly, the present invention is to solve the above-mentioned problems of the prior art, and an object of the present invention is to provide a suspension and an HGA capable of more effectively dissipating heat from an IC chip.

[0009]

According to the present invention, an elastic stainless steel flexure for supporting a magnetic head slider having at least one thin film magnetic head element, and a flexure supporting the flexure are provided. A load beam made of stainless steel for applying a predetermined load to the slider, a wiring member which is formed directly on the flexure and on which an IC chip mounting a circuit for a thin film magnetic head element is mounted, and A high thermal conductivity member having a higher thermal conductivity than stainless steel fixed to the back surface of the flexure in a region including at least the portion to be mounted, wherein the load beam has a through hole, and the high thermal conductivity member is provided. Is provided in the through hole.

According to the present invention, there is further provided a magnetic head slider having at least one thin-film magnetic head element,
A flexure made of stainless steel having elasticity for fixing the magnetic head slider, a load beam made of stainless steel for supporting the flexure and applying a predetermined load to the magnetic head slider, and a circuit for the thin film magnetic head element. The mounted IC chip, the wiring member directly formed on the flexure, the wiring member on which the IC chip is mounted, and the stainless steel fixed to the back surface of the flexure in a region including at least the portion where the IC chip is mounted. High thermal conductivity member with high thermal conductivity,
An HGA is provided in which the load beam has a through hole and a high thermal conductivity member is inserted into the through hole.

A high thermal conductivity member having a higher thermal conductivity than stainless steel is inserted into a through hole formed in the load beam, and is placed on the back surface of the flexure in a region including at least a portion where an IC chip is mounted or mounted. It is fixed. Therefore, not only the heat capacity of the suspension is increased, but also the heat generated by the high thermal conductivity member can be diffused and cooled over a wide area, so that the temperature of the IC chip itself can be reduced and the temperature of the IC chip itself can be reduced. Local temperature rise of the surrounding suspension can also be suppressed. As a result, the operation of the IC circuit can be stabilized, the thermal deformation of the suspension can be prevented, and the adverse effect of heat on the thin-film magnetic head element can be prevented.

It is preferable that a gap is provided between the high thermal conductivity member and the load beam in the through hole so that the high thermal conductivity member does not contact the load beam. As a result, the IC chip mounting portion of the flexure is thermally separated to some extent from the other portions of the flexure and the load beam, and the load beam is prevented from being thermally deformed such as expansion and contraction due to the heat generated by the IC chip. it can. Further, by providing the gap, it is possible to prevent the high thermal conductivity member from being thermally expanded and coming into contact with the load beam.

The high thermal conductivity member is made of Al, Cu, Mg, A
It is preferable that the metal member includes at least one selected from the group consisting of an alloy, a Cu alloy, and a Mg alloy.

It is preferable that the high thermal conductivity member is fixed to the flexure by an adhesive or spot welding.

[0015] It is preferable that a base plate fixed to the base of the load beam is further provided.

[0016]

FIG. 1 is a perspective view showing a schematic structure of an HGA according to an embodiment of the present invention, and FIG.
FIG. 3 is a side view of the HGA viewed from the lateral direction, and FIG. 4 is an exploded side view of the HGA.

As shown in these figures, the HGA has a magnetic head slider 11 provided with at least one thin-film magnetic head element fixed to a tip end of a suspension 10 and a head drive and readout at an intermediate position of the suspension 10. It is configured by mounting an IC chip 12 for signal amplification. The magnetic head slider 11 and the IC chip 12
The suspension 10 is mounted on the surface of the suspension 10 facing the magnetic disk medium so as to face the surface of the magnetic disk medium.

The suspension 10 has an elastic flexure 13 for supporting the magnetic head slider 11 at one end and supporting the IC chip 12 at an intermediate portion thereof, and supports and fixes the flexure 13, which is also elastic. The load beam 14, a base plate 15 provided at the base of the load beam 14, and the high thermal conductivity member 1 having a higher thermal conductivity than stainless steel fixed to the back surface of the flexure 13.
6 mainly.

The magnetic head slider 11 has at least one thin-film magnetic head element formed by a write head element and an MR read head element. The size of the magnetic head slider 11 is merely an example, but it is 1.25.
mm × 1.0 mm × 0.3 mm.

In the IC chip 12, a drive circuit as a head amplifier and a read signal amplifying circuit are mounted as ICs. Although the size of the IC chip 12 is merely an example, it is 1.4 mm × 1.0 mm × 0.13 mm. Thus, the IC chip 12 has a very small and thin shape.

The flexure 13 has a soft tongue 13a centered on a dimple provided on the load beam 14, and has elasticity for stably supporting the magnetic head slider 11 with the tongue 13a to stabilize the flying attitude. ing. In this embodiment, the flexure 13 has a thickness of about 2 mm.
It is made of a 5 μm stainless steel plate (for example, SUS304TA), and is formed into a shape having a substantially uniform width.

On the flexure 13, a thin film pattern is directly formed by the same known patterning method as used for forming a printed circuit board on a thin metal plate. This thin film pattern constitutes a plurality of lead conductors and connection pads as wiring members, and one end of each of these lead conductors is provided at one end (tip) of the flexure 13 as a terminal electrode of the magnetic head slider 11. The other end is connected to an external circuit connection pad 18 provided at the other end (rear end) of the flexure 13. The connection pad 19 of the IC chip 12 is formed in the middle of the lead conductor.

The back surface of the flexure 13 has at least I
The high thermal conductivity member 16 is tightly fixed so as to cover the area where the C chip 12 is mounted. For this fixation, adhesion by an adhesive or spot welding using a laser or the like is used. In the case of attachment by bonding, it is more preferable to use an adhesive having good thermal conductivity, for example, a silver paste-based adhesive.

The high thermal conductivity member 16 is a plate-shaped or block-shaped member formed of a material having higher thermal conductivity than stainless steel, and in this embodiment, an Al plate is used. The high thermal conductivity member 16 is most preferably an Al plate in terms of high thermal conductivity, light weight, and corrosion resistance, but is not limited thereto.
A metal plate member including one selected from u, Mg, Al alloy, Cu alloy and Mg alloy can be used.

The load beam 14 has elasticity for pressing the magnetic head slider 11 in the direction of the magnetic disk to stabilize the flying height. This load beam 14
Is about 60-65 μm with a width narrowing toward the tip
It is made of a thick stainless steel plate having elasticity, and supports the flexure 13 over its entire length. The load beam 14 has a large through hole 14 a formed along the flexure 13.

The high thermal conductivity member 16 fixed to the back surface of the flexure 13 is inserted into the through hole 14a.
Therefore, even if the high thermal conductivity member 16 is additionally provided, the height (thickness) of the suspension 10 hardly increases. In addition, the high thermal conductivity member 16 is
Is inserted in a non-contact state. That is, the through hole 14 a is formed to be larger than the high thermal conductivity member 16, so that a gap is formed between the high thermal conductivity member 16 and the load beam 14. Thereby, flexure 13
The portion where the high thermal conductivity member 16 is fixed is thermally separated to some extent from the other portion of the flexure 13 and the load beam 14, and the load beam 14 expands and contracts due to the heat generated by the IC chip 12. Can be almost prevented from being thermally deformed. Also, by providing the gap, it is possible to prevent the high thermal conductivity member 16 from thermally expanding and coming into contact with the load beam 14.

The high thermal conductivity member 16 may have such a thickness that it can be accommodated in the through hole 14a. However, as shown in FIG. 3, the high thermal conductivity member 16 has a thickness that protrudes from the through hole 14a. This is preferable because the heat capacity is increased. High thermal conductivity member 1
In the case where an Al plate is used as 6, a lightweight Al plate is inserted into the portion removed by the load beam 14 g through-hole 14 a made of stainless steel.
The overall mass is reduced and the mechanical properties are improved. vice versa,
It is also possible to further increase the heat capacity and the surface area by increasing the thickness of the high thermal conductivity member 16 by the reduced weight.

Note that, as in the present embodiment, the flexure 1
In a three-piece suspension in which the load beam 3 and the load beam 14 are independent components, the rigidity of the load beam 14 is higher than the rigidity of the flexure 13.

The base plate 15 is provided with the load beam 14.
It is made of thicker stainless steel and is fixed to the base of the load beam 14 by welding. By fixing the mounting portion 15a of the base plate 15 to a support arm (not shown) by mechanical caulking, H
The GA is mounted on the support arm.

At an intermediate position of the flexure 13, the IC chip 12 is mounted on the wiring member on the same surface as the surface on which the slider 11 is mounted (on the surface facing the magnetic disk medium). As shown in FIGS. 3 and 4, the IC chip 12 is a bare chip, and the IC chip connection pads 19 provided on a conductor pattern formed on the flexure 13 via an insulating material layer such as polyimide. Is flip-chip mounted by, for example, a gold ball 20. The gap between the bottom surface of the IC chip 12 and the thin film pattern is filled with an underfill layer for improving heat radiation characteristics, improving mechanical strength, and covering the IC chip 12.

As described above, although the IC chip 12 is very small and thin, it has several tens mA.
A large amount of heat is generated in order to allow the writing current to flow. In the suspension of the conventional structure, this heat not only affects the IC chip itself, but also affects the MR head element and locally applies the stainless steel constituting the flexure and load beam which are spring members of the suspension. Heating problem. Although the IC chip can be somewhat cooled by the air cooling effect by the rotation of the magnetic disk, the air cooling effect cannot be expected so much because the IC chip itself has a very small surface area. Also, since the clearance between the IC chip and the surface of the magnetic disk is very small, there is also a meaning of completely suppressing the contact with the surface of the magnetic disk, and measures to further enhance the air cooling effect have been taken.
It is difficult to apply to the C chip side.

Therefore, in the suspension having the conventional structure, the heat of the IC chip is conducted to the suspension via the terminal portion made of gold or solder. However, since heat conduction hardly occurs in the suspension having low thermal conductivity, heat is hardly dissipated. Otherwise, this part of the suspension will be locally hot.

On the other hand, in the present embodiment, the heat conductivity of the flexure 13 at the area including at least the position where the IC chip 12 is mounted is passed through the through-hole 14 a formed in the load beam 14. Since the high high thermal conductivity member 16, that is, the Al plate is inserted and fixed, the IC
The heat generated in the chip 12 is conducted throughout the Al plate 16 and diffused over a wide area, so that the IC chip 12 can be effectively cooled. Also, this Al plate 16
Since the heat capacity of the suspension increases by itself acting as a heat sink, the cooling of the IC chip 12 is promoted in that sense as well.

Actually, when the entire load beam is made of a stainless steel plate and the Al plate is not inserted,
Assuming that the temperature of the C chip is 100%, the load beam 14
Plate 1 fixed to flexure 13 in through hole 14a
It has been confirmed that the temperature of the IC chip when 6 is inserted is considerably reduced to about 82.6%.

As described above, the temperature of the IC chip itself can be reduced, and the local temperature rise of the surrounding suspension can be suppressed. As a result, the operation of the IC circuit can be stabilized, the thermal deformation of the suspension can be prevented, and the adverse effect of heat on the thin-film magnetic head element can be prevented. Moreover, the space between the HGA and the magnetic disk is not hindered.

As the thickness of the Al plate 16 increases, the heat capacity increases and the thermal conductivity increases, so that the heat radiation improves. However, if the Al plate 16 is too thick, the mechanical properties of the suspension deteriorate because the weight increases. Therefore, the upper limit of thickness is 500μ
m. In addition, the larger the area of the Al plate 16, the larger the heat capacity and the larger the surface area exposed to the air, so that the heat radiation becomes better.

In the HGA of this embodiment, after each suspension is manufactured, the Al plate is passed through the through hole 14a of the load beam 14 and the Al plate is flexed by the flexure 13 by any method.
It can be manufactured only by adding the operation of fixing to the back surface of the conventional process to the conventional process, so that the manufacturing process does not become complicated. Therefore, an HGA capable of more effectively dissipating heat from an IC chip without increasing manufacturing cost and manufacturing time.
Can be manufactured.

The above-described embodiments are all illustrative of the present invention and not restrictive, and the present invention can be embodied in various other modified forms and modified forms. Therefore, the scope of the present invention is defined only by the appended claims and their equivalents.

[0039]

As described above in detail, according to the present invention, a high thermal conductivity member having a higher thermal conductivity than stainless steel is inserted into a through hole formed in a load beam, and
It is fixed to the back surface of the flexure in a region including at least a portion where the C chip is mounted or mounted.
Therefore, not only the heat capacity of the suspension is increased, but also the heat generated by the high thermal conductivity member can be diffused and cooled over a wide area, so that the temperature of the IC chip itself can be reduced and the temperature of the IC chip itself can be reduced. Local temperature rise of the surrounding suspension can also be suppressed.
As a result, the operation of the IC circuit can be stabilized, the thermal deformation of the suspension can be prevented, and the adverse effect of heat on the thin-film magnetic head element can be prevented.

Also, by providing a gap between the high thermal conductivity member and the load beam in the through hole so that the high thermal conductivity member does not contact the load beam, the IC chip mounting portion of the flexure can be connected to another flexure. It becomes thermally separated and independent to some extent from the portion and the load beam, and it is possible to prevent the load beam from being thermally deformed such as expansion and contraction due to the heat generated by the IC chip. Further, by providing the gap, it is possible to prevent the high thermal conductivity member from being thermally expanded and coming into contact with the load beam.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a schematic structure of an HGA according to an embodiment of the present invention.

FIG. 2 is an exploded perspective view of the HGA in the embodiment of FIG.

FIG. 3 is a side view of the HGA in the embodiment of FIG. 1 as viewed from a lateral direction.

FIG. 4 is an exploded side view of the HGA in the embodiment of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Suspension 11 Magnetic head slider 12 IC chip 13 Flexure 13a Tongue part 14 Load beam 14a Through hole 15 Base plate 15a Attachment part 16 High thermal conductivity plate member, Al plate 17 Head connection pad 18 External circuit connection pad 19 IC chip connection Pad 20 gold ball

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ken Wada 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Corporation (72) Inventor Norioka Ota 1-13-1 Nihonbashi, Chuo-ku, Tokyo TDK Co., Ltd. (72) Inventor Takashi Honda 1-13-1, Nihonbashi, Chuo-ku, Tokyo TDC Corporation F-term (reference) 5D042 NA02 PA01 PA09 TA07 TA09 5D059 AA01 BA01 CA26 CA29 DA26 DA33 DA36 EA08

Claims (12)

[Claims] 1. A flexure made of stainless steel having elasticity for supporting a magnetic head slider having at least one thin-film magnetic head element, and a flexure supporting the flexure for applying a predetermined load to the magnetic head slider. And a wiring member formed directly on the flexure, on which the IC chip mounting the circuit for the thin-film magnetic head element is mounted, and a portion on which the IC chip is mounted. A high thermal conductivity member having a higher thermal conductivity than stainless steel fixed to the back surface of the flexure in at least a region including the load beam, the load beam has a through hole, and the high thermal conductivity member is A suspension characterized by being inserted into a through hole. 2. A gap is provided between the high thermal conductivity member and the load beam in the through hole so that the high thermal conductivity member does not contact the load beam. The suspension according to claim 1. 3. The suspension according to claim 1, wherein the high thermal conductivity member is fixed to the flexure with an adhesive. 4. The suspension according to claim 1, wherein the high thermal conductivity member is fixed to the flexure by spot welding. 5. The high thermal conductivity member is made of Al, Cu, M
g, 1 selected from Al alloy, Cu alloy and Mg alloy
The suspension according to any one of claims 1 to 4, wherein the suspension is a metal member including a seed. 6. The apparatus according to claim 1, further comprising a base plate fixed to a base of the load beam.
The suspension according to any one of claims 1 to 5, wherein 7. A magnetic head slider having at least one thin-film magnetic head element, a flexure made of elastic stainless steel for fixing the magnetic head slider, and supporting the flexure. A load beam made of stainless steel for applying a predetermined load, an IC chip mounted with a circuit for the thin-film magnetic head element, and a wiring member formed directly on the flexure and mounted with the IC chip When,
A high thermal conductivity member having a higher thermal conductivity than stainless steel fixed to the back surface of the flexure in a region including at least a portion where the IC chip is mounted, wherein the load beam has a through hole. A head gimbal assembly, wherein the high thermal conductivity member is inserted into the through hole. 8. A gap is provided between the high thermal conductivity member and the load beam in the through hole so that the high thermal conductivity member does not contact the load beam. 8. The head gimbal assembly according to claim 7. 9. The head gimbal assembly according to claim 7, wherein the high thermal conductivity member is fixed to the flexure with an adhesive. 10. The head gimbal assembly according to claim 7, wherein the high thermal conductivity member is fixed to the flexure by spot welding. 11. The high thermal conductivity member is made of Al, Cu,
The head gimbal assembly according to any one of claims 7 to 10, wherein the head gimbal assembly is a metal member including one selected from Mg, an Al alloy, a Cu alloy, and a Mg alloy. 12. The head gimbal assembly according to claim 7, further comprising a base plate fixed to a base of the load beam.