The present invention relates to information recording disk drive devices, and more particularly to a suspension capable of releasing thermal deformation thereof and suppressing thermal crown change of a slider mounted thereon. The present invention also relates to a head gimbal assembly and a disk drive unit with the suspension.
One known type of information storage device is a disk drive device that uses magnetic media to store data and a movable read/write head that is positioned over the media to selectively read from or write to the disk.
a illustrates a conventional disk drive device and shows a magnetic disk 101 mounted on a spindle motor 102 for spinning the disk 101. A voice coil motor arm 104 carries a head gimbal assembly (HGA) 100 that includes a slider 103 incorporating a read/write head. A voice-coil motor (VCM, not labeled) is provided for controlling the motion of the motor arm 104 and, in turn, controlling the slider 103 to move from track to track across the surface of the disk 101, thereby enabling the read/write head to read data from or write data to the disk 101. In operation, a lift force is generated by the aerodynamic interaction between the slider 103 and the spinning magnetic disk 101. The lift force is opposed by equal and opposite spring forces applied by the HGA 100 such that a predetermined flying height above the surface of the spinning disk 101 is maintained over a full radial stroke of the motor arm 104.
Now referring to
The load beam 106 is connected to the base plate 108 by the hinge 107. A locating hole 112 is formed on the load beam 106 for aligning the load beam 106 with the flexure 105. As best shown in
The base plate 108 is used to enhance structure stiffness of the whole HGA 100. A mounting hole 113 is formed on end of the base plate 108 for mounting the whole HGA to the motor arm 104 (refer to
The flexure 105 runs from the hinge 107 to the load beam 106. The flexure 105 has a proximal end 119 adjacent the hinge 107 and a distal end 118 adjacent the load beam 106. A locating hole 117 is formed on the distal end 118 of the flexure 105 and aligned with the locating hole 112 of the load beam 106, thus obtaining a high assembly precision.
d shows the tip part of the flexure 105 and illustrates the top-face side of the flexure 105 on which the slider 103 is mounted. As shown in
The suspension tongue 116 and the slider 103 are securely fixed by an adhesive filled therebetween. Further, there are cases of using solder for fixing the slider 103, whether or not the adhesive is used.
e illustrates the slider 103 flying above the magnetic disk 101 when the HDD is working. In a common disk drive unit, the slider flies only approximately a few micro-inches above the surface of the rotating disk. Generally, the flying height “h” of the slider, shown in
With reduction of the flying height, it is strongly expected that the flying height be kept constant all the time regardless of variable flying conditions, since great variation of flying height will deteriorate reading/writing performance of the slider, and in worse cases even result in data reading/writing failure.
If coefficients of thermal expansion (CTE) of the slider 103 and the flexure 105 are different, the slider 103 may have a warp and distortion in accordance with deformation of the suspension tongue 116 caused by heat.
The deformation of the slider 103 described above can also happen in the case where the suspension tongue 116 and the slider are securely fixed by adhesive.
f shows a stress distribution of the thermal expansion caused in the flexure 105 when the flexure 105 in the shape of
The deformation of the slider will cause the variation of the flying height thereof, thereby badly affecting reading/writing performance of the slider. Further, the deformation may cause crack of the solder, thereby cutting the electrical connection of the slider 103 and the flexure 105. Therefore, it is necessary to control the deformation to a tolerant limit.
Referring to
Hence, a need has arisen for providing an improved suspension which can release thermal deformation of the suspension tongue and suppress thermal crown change of a slider mounted thereon.
Accordingly, one objective of the present invention is to provide a suspension capable of releasing thermal deformation of the suspension tongue and, in turn, preventing thermal crown change of the slider, thereby improving the flying performance of the slider.
Another objective of the present invention is to provide a HGA with a suspension which can suppress the thermal crown change of the slider, thus achieving stable writing and reading of data.
Still another objective of the present invention is to provide a HDD with a HGA which is capable of improving the flying performance of the slider, thereby improving the read/writing performance of the HDD.
To achieve the above-mentioned objective, a suspension for a HGA comprises a flexure having a suspension tongue with electrical pads adapted for mounting a slider thereon. The suspension tongue has some portions etched with left portions therebetween forming into at least one hinge or spring mechanism for releasing thermal deformation of the suspension tongue and suppressing thermal crown change of the slider.
The suspension tongue has a trailing portion bonded to a trailing edge of the slider and a leading portion bonded to a leading edge of the slider.
In an embodiment of the suspension according to the present invention, the electrical pads are disposed on the trailing portion and bonded to the trailing edge of the slider by solder or gold ball bonding, and the leading portion are bonded to the leading edge of the slider by epoxy or other adhesive materials.
In another embodiment of the suspension according to the present invention, the electrical pads comprise trailing pads disposed on the trailing portion of the suspension tongue and bonded to the trailing edge of the slider by solder or gold ball bonding and leading pads disposed on the leading portion of the suspension tongue and bonded to the leading edge of the slider by solder or gold ball bonding.
The etched portions comprise a first group of slots defined adjacent to the trailing portion and a second group of slots defined adjacent to the leading portion.
Selectively, the first group of slots is a closed slot semi-surrounding the trailing portion or two closed slots surrounding the trailing portion. The second group of slots forms into a stairway configuration. Selectively, the second group of slots has an H-shaped, M-shaped, or X-shaped configuration.
Furthermore, the second group of slots comprises a pair of one-end-opened slots formed therebetween.
A HGA of the present invention comprises a suspension comprising a flexure having a suspension tongue with electrical pads thereon, and a slider mounted on the suspension tongue by the electrical pads. The suspension tongue has some portions etched with left portions therebetween forming into at least one hinge or spring mechanism for releasing thermal deformation of the suspension tongue and suppressing thermal crown change of the slider.
A HDD of the present invention comprises a HGA, a drive arm connected to the HGA, a disk, and a spindle motor operable to spin the disk. The HGA includes a slider and a suspension supporting the slider. The suspension comprises a flexure having a suspension tongue with electrical pads thereon for mounting the slider. The suspension tongue has some portions etched with left portions therebetween forming into at least one hinge or spring mechanism for releasing thermal deformation of the suspension tongue and suppressing thermal crown change of the slider.
Since the suspension has some portions etched with left portions therebetween forming into hinge or spring mechanism, when the temperature changes, the thermal deformation of the suspension can be released by contracting or expanding constrained in the etched portions which, in turn, suppresses deformation of the slider caused by the mismatch of CTE, thereby improving flying stability of the slider, and finally improving reading/writing characteristics of the slider and performance of the entire disk drive device.
Other aspects, features, and advantages of this invention will become apparent from the following detailed description when taken in conjunction with the accompanying drawings, which are a part of this disclosure and which illustrate, by way of example, principles of this invention.
The accompanying drawings facilitate an understanding of the various embodiments of this invention. In such drawings:
a is a top plan view of a conventional HDD;
b is a perspective view of a conventional HGA;
c is an exploded perspective view of the HGA shown in
d is a partial top plan view of a flexure of the HGA shown in
e shows the HGA working above a disk;
a is a schematic view illustrating the state of a flexure and a slider mounted on the flexure;
b is a schematic view illustrating the deformation of the slider and the flexure shown in
c is a schematic view illustrating the deformation of the slider and the flexure shown in
d-2e are schematic views illustrating solder crack under the deformation of the slider and the flexure;
f shows a stress distribution of the thermal expansion caused in the flexure shown in FIG id when it is heated to 55° C.
a is a schematic view of a suspension tongue with H-shaped slot according to a first embodiment of the present invention;
b is a partial top plan view of the suspension with H-shaped slot according to the first embodiment of the present invention;
a is a partial top plan view illustrating the state of the suspension with H-shaped slot shown in
b is a partial top plan view illustrating the state of the suspension with H-shaped slot shown in
a is a graph showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism when temperature increases;
b is a graph showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism when temperature decreases;
c is a graph showing the maximum stress of the solder or gold ball connecting the suspension with the slider under 2000 G shock;
a is a schematic view of a suspension tongue of a flexure of a suspension according to a second embodiment of the present invention;
b is a partial top plan view of the suspension shown in
a is a partial top plan view illustrating the state of the suspension shown in
b is a partial top plan view illustrating the state of the suspension shown in
a is a side view showing a slider mounted on the present suspension only by solder or gold ball without using epoxy or other adhesive materials, which will be called epoxy free design hereinafter;
b is a side view showing a slider mounted on the suspension by using epoxy or other adhesive materials between the suspension and the slider, which will be called epoxy design hereinafter;
a is a graph for showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism of the flexure shown in
b is a graph for showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism of the flexure shown in
c is a graph for showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism of the flexure shown in
d is a graph for showing the relationship between total crown changes of the slider and the length of the movable portion of the hinge or spring mechanism of the flexure shown in
a is a schematic view of a suspension tongue of a flexure of the suspension according to a third embodiment of the present invention;
b is a partial top plan view of the suspension shown in
a is a partial top plan view illustrating the state of the suspension shown in
b is a partial top plan view illustrating the state of the suspension shown in
a is graph showing the relationship between total crown changes of the slider and the movable portion of the hinge or spring mechanism of the flexure shown in
b is a graph showing the relationship between total crown changes of the slider and the movable portion of the hinge or spring mechanism of the flexure shown in
Various preferred embodiments of the invention will now be described with reference to the figures, wherein like reference numerals designate similar parts throughout the various views. As indicated above, the invention is directed to a suspension capable of releasing thermal deformation thereof and, in turn, preventing or reducing deformation of the slider, thereby improving flying stability of the slider, and finally improving reading/writing characteristics of the slider and performance of entire disk drive device.
a and 4b show a tip portion of the suspension of a first embodiment according to the present invention. As shown in
The suspension tongue 516 has some portions etched which will be called etched portions hereinafter with left portions therebetween forming into a plurality of hinge or spring mechanisms 558. The etched portions include two groups of slots. The first group of slots of the flexure 505 is a closed slot 553 semi-surrounding the trailing pads 582. The second group of slots that defines the hinge or spring mechanism 558 are slots 551, 552. The slot 551 is H-shaped and formed in a closed-state within the suspension tongue 516 adjacent to the leading pads 583. The two slots 552 each have one end opened, which are called one-end-opened slot, and are formed by cutting two opposite sides of the suspension tongue 516 and extending between two branches of the H-shaped slot 551.
a-5b illustrate that how the suspension tongue 516 releases the internal stress and thermal deformation when environment temperature changes.
Referring to
Referring to
Referring to
Typically, a slider is bonded to a suspension by epoxy or other adhesive materials and electrically connected at electrical pads between the slider and the suspension, which is called epoxy design. Without epoxy, the slider is attached on the suspension by the solder or gold ball bonding only, which is called epoxy free design.
As shown in
a shows a slider 203 being mounted on the flexure 505 of the suspension according to the present invention only by solder or gold balls 231, 232, and
a-8b illustrate the work principle of the suspension of the second embodiment of the present invention. As shown in
Referring to
a-10b show the relation between thermal crown changes and H2 values under epoxy free design. Taken a 170 um thin Pemto slider as example too, we can see from the
c-10d show the relation between thermal crown changes and H2 values under epoxy design. For the 170 um thin Pemto slider, it is found that when H2 equals to 140 um, slider total crown change can be reduced to zero during temperature is raised up to 55 degree C. in
a-11b show the shape of the etched portions on the flexure 705 of a third embodiment of the suspension according to the present invention. The first group of slots is a closed slot 754 semi-surrounding the trailing portion 781, and the second group of slots is two C-shaped slots 751, 752 back to back to form an X-shaped configuration adjacent to the leading portion 780 and two one-end-opened slots 753 formed between the closed slots 751, 752 by cutting two sides of the suspension tongue 716 respectively.
Referring to
Similar to the suspensions of the first and second embodiments, the length H3 of the movable portion of the hinge or spring mechanism 758 can be adjusted to reduce the crown change of the slider.
The configuration of the etched portions defined on the suspension tongue by through slots is not necessarily the above-mentioned shape, other stairway geometries with one-hinge or multi-hinge mechanical function can be used in order to release the thermal deformation of the suspension and reduce the slider thermal crown change during thermal shock.
Since the suspension has hinge or spring mechanisms as described above, when the temperature changes, the thermal deformation of the suspension can be released by contracting or expanding around the movable portion of the hinge or spring mechanisms which, in turn, prevents or reduces crown deformation of the slider, thereby improving flying stability of the slider, and finally improving reading/writing characteristics of the slider and performance of the entire disk drive device.
Now, referring to
Referring to
The foregoing description of the present invention has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the invention to the precise form disclosed, and obviously many modifications and variations are possible in light of the above teaching. Such modifications and variations that may be apparent to those skilled in the art are intended to be included within the scope of this invention as defined by the accompanying claims.
Number | Date | Country | Kind |
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200710147476.8 | Sep 2007 | CN | national |