JP2002216327A - Head suspension and method of mounting IC chip - Google Patents

Abstract

[PROBLEMS] To reduce an inductance component between a head and a preamplifier in order to realize a high transfer rate of a magnetic disk drive. SOLUTION: In order to mount a preamplifier on a surface of a suspension near a head opposite to a head slider, an opening is provided in the suspension and a wiring pattern is routed and the preamplifier is flip-chip mounted.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnetic disk drive suspension and preamplifier IC mounting method for magnetically recording and reproducing information, and more particularly to a magnetic disk drive suspension suitable for high-speed transfer in high-density recording. The present invention relates to a preamplifier IC mounting method.

[0002]

2. Description of the Related Art Conventionally, a preamplifier IC for a head for a magnetic disk drive has a preamplifier mounted by wire bonding or flip chip mounting on an FPC (Flexible).
e Printed Circuit), the preamplifier is protected by epoxy resin, and the FPC is mounted on the carriage. Further, a pad for connection with the recording / reproducing head is formed at the head side end on the FPC, and the connection between the FPC and the head is made by an FPC for connection or a gold-plated copper wire coated with urethane or the like. is there. Such a technique is disclosed in, for example, Japanese Patent Application Laid-Open No. H11-149626.

On the other hand, the density of magnetic disk devices is increasing year by year, and in order to realize a high transfer rate, it is necessary to reduce an inductance component by shortening a wiring length between a head and a preamplifier. However, even if the preamplifier is mounted on the head-side end of the FPC, in a magnetic disk drive on which a 2.5-inch or 3.5-inch magnetic disk is mounted, the dimensions of the carriage arm and the suspension are long. There is a problem that it is difficult to reduce the wiring length between the head and the preamplifier.

Therefore, in order to reduce the inductance between the head and the preamplifier, that is, to reduce the wiring length, it is necessary to mount components such as a preamplifier and capacitors and resistors near the head, that is, on the suspension. In addition, as the recording density of the magnetic disk has been improved, the head flying height has been reduced and the height of the head slider has been reduced, so that the head-magnetic disk space has been narrowed. It must be mounted in the direction opposite to the slider direction. As a technique for such a structure, Japanese Patent Application Laid-Open No. 11-273044 discloses a suspension in which a head slider is mounted on an upper surface and a head IC chip is mounted on a lower surface. However, in the structure proposed here, it is necessary to connect the wiring pattern on the upper surface and the terminal through a plurality of through holes, and there is a problem that the process is complicated.

[0005] Further, there is another problem that the impact resistance to a preamplifier IC or the like mounted on the suspension is ensured.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a suspension and a manufacturing process in which a preamplifier IC is mounted in the vicinity of the head, that is, on the suspension, and the impact resistance to the preamplifier IC mounted in the vicinity is ensured. Of a suspension capable of avoiding the complication of the preamplifier, and a preamplifier I mounted on the suspension
C is to provide a mounting method.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a head slider for mounting a head slider on a suspension, on which a wiring pattern for a preamplifier IC for controlling recording and reproduction of the head on the head slider side is provided. This is achieved by a suspension having a preamplifier IC chip mounting pad for mounting a preamplifier IC chip on the side opposite to the head slider side by bending the wiring pattern formed on the head slider side and having an opening drawn around on the side opposite to the side.

Further, the object of the present invention is achieved by a suspension characterized in that the mounting pad is a flip chip mounting pad.

Further, the object of the present invention is achieved by a suspension characterized in that a reinforcing plate is attached to the side opposite to the head slider and around the preamplifier IC.

Another object of the present invention is to inject a resin into the preamplifier circuit surface through the suspension opening for mounting the preamplifier mounted on the suspension, fill the space between the preamplifier and the suspension, and seal the preamplifier integrated circuit surface. This is achieved by a flip chip mounting method.

[0011]

FIG. 1 shows a cross-sectional view of mounting a preamplifier IC on a suspension according to one embodiment of the present invention. In FIG. 1, 2 is a suspension opening,
Reference numeral 53 denotes a wiring pattern. The wiring pattern 53 is routed from the head slider side (the upper surface of the suspension 1) to the opposite side (the lower surface of the suspension 1) from the head slider side by the suspension opening 2. The preamplifier IC 7 is embedded with the resin 80 and has a structure in which the impact resistance is improved by the reinforcing plate 50.

FIG. 2 is a perspective view of the suspension 1 on which the preamplifier IC 7 (not shown in FIG. 2) is mounted and the head slider 3 to the carriage arm 6 from the head slider side. The suspension opening 2 is arranged near the head slider 3. FIG. 3 is a perspective view showing the configuration from the side opposite to the head slider.

In these figures, a suspension 1 is a stainless steel plate, and a wiring pattern 10 for electrically connecting a head and a preamplifier IC 7 is provided on a surface on a head slider 3 side.
And wiring patterns 14-2 for electrically connecting preamplifier IC 7 and relay FPC connection pads 61-67
0, and a preamplifier IC 7 is provided on the surface opposite to the head slider.
Have pads 21 to 31 for mounting. The suspension 1 is provided with the head slider side surface wiring patterns 10 to 20 by the preamplifier mounting pads 21 to 3.
One opening 2 for leading to 1 is formed in the vicinity of the head slider, the shape is a quadrangle having the same shape as the preamplifier 7, and each side of the opening 2 is shorter than each side of the preamplifier IC 7, and the opening shown in FIG. The second cuts 47 and 48 are not sharp but rounded.

FIG. 5 shows a cross-sectional structure of a wiring pattern formed on the suspension.
It has a wiring pattern 44 such as a copper foil on the upper surface and is covered with a cover layer 45 made of polyimide. However, preamplifier I
The above-mentioned polyimide cover layer 45 is opened in the pad 46 for mounting the C7. The head slider opposite surface wiring pattern 71 having the preamplifier 7 mounting pads 46 formed on the head slider surface is mechanically bent 180 degrees to the head slider opposite surface as shown in FIG. Can be attached well.

In the present invention, the preamplifier IC 7 mounted on the surface of the suspension 1 opposite to the head slider is of a face-down flip-chip type and has a surface 52 (FIG. 3).
And an integrated circuit is formed on the integrated circuit.
2 are formed and the integrated circuits other than the connection surfaces of the minute bumps 32 to 34 are covered with a protective film. The dimension of one side of the preamplifier 7 is 1 mm or less, and the thickness is 0.3 mm or less. Arrangement of Micro Bumps 32 to 42 of Preamplifier 7 and Preamplifier I
The arrangement of the C mounting pads 21 to 31 coincides with each other, and the micro bumps of the preamplifier IC 7, for example, 32 and 38, are optically recognized for their placement, and the preamplifier IC mounting pads, for example 21 and 27, are optically recognized for their placement. The IC 7 is accurately mounted on the side of the suspension 1 opposite to the head slider, and is mounted by thermocompression bonding.

In the gap between the preamplifier IC 7 and the suspension 1, the epoxy resin 80 sprayed from a nozzle or the like to the integrated circuit surface 43 of the preamplifier IC 7 from the opening 2 of the suspension 1 through a nozzle or the like, the gap between the preamplifier IC 7 and the suspension, the minute bump 32 of the preamplifier IC 7. To 42 and the integrated circuit surface of the preamplifier 7 are filled without gaps.

FIG. 4 shows an embodiment in which a reinforcing plate 50 is attached to the suspension 1 on the side opposite to the head slider and around the preamplifier 7 according to the present invention. Reinforcement plate opening 5
The dimension of 4 is larger than the dimension of preamplifier 7,
The thickness of the reinforcing plate 50 is smaller than the thickness of the preamplifier IC 7.
The reinforcing plate 50 is attached to the suspension 1 mechanically or by bonding after forming the wiring pattern 53 on the suspension 1 and before mounting the preamplifier IC 7.

In the magnetic disk drive equipped with the suspension obtained by this embodiment, the transfer speed is 10
0 MB / s and a wiring inductance of 25 nH were obtained. On the other hand, when a conventional suspension in which the preamplifier is mounted on the head-side end of the FPC is used, the transfer speed is 60 MB / s and the wiring inductance is 1
00nH.

[0019]

By mounting a preamplifier near the head, a low inductance between the preamplifier and the head can be realized, and a high-speed transfer speed can be realized in the magnetic disk drive.

[Brief description of the drawings]

FIG. 1 is a diagram showing a cross-sectional structure of a preamplifier mounting portion of a suspension according to an embodiment of the present invention.

FIG. 2 is a head-side perspective view of the entire suspension of the present invention.

FIG. 3 is an enlarged view of a preamplifier mounting portion of the present invention.

FIG. 4 is a perspective view of a preamplifier mounting portion by attaching a reinforcing plate according to an embodiment of the present invention.

FIG. 5 is a diagram showing a cross-sectional structure of a wiring pattern formed on a suspension according to the present invention.

[Explanation of symbols]

1 ... suspension, 2 ... suspension opening, 3 ...
Head slider, 4 ... Head slider mounting part, 5 ...
Suspension connection part, 6: Carriage arm, 7: Preamplifier IC, 10 to 13: Wiring pattern between head and preamplifier, 14 to 20: Preamplifier-relay FPC connection pattern, 21 to 31: Preamplifier mounting pad, 32
42, preamplifier micro-bumps, 43, polyimide insulating layer, 44, wiring pattern, 45, polyimide cover layer, 46, polyimide cover opening, 47, 48
... Suspension opening cutout, 50 ... Reinforcement plate, 51 ... Flange part, 52 ... Preamplifier integrated circuit surface, 53 ... Wiring pattern, 54 ... Reinforcement plate opening, 61-67 ... Relay FPC connection pad, 70 ... Head slider surface wiring pattern , 7
1: Wiring pattern on head opposite surface, 80: Resin.

Claims (4)

[Claims] 1. A suspension for mounting a head slider on which a head is mounted, having an opening for routing a wiring pattern for a preamplifier IC on the head slider side for controlling recording / reproduction of the head to a side opposite to the head slider side. A head suspension having a preamplifier IC chip mounting pad for bending a wiring pattern formed on a head slider side to mount a preamplifier IC chip on a side opposite to the head slider side. 2. The head suspension according to claim 1, wherein said mounting pad is a flip chip mounting pad. 3. The head suspension according to claim 1, wherein a reinforcing plate is attached to the side opposite to the head slider and around the preamplifier IC. 4. A wiring pattern for connecting to a preamplifier IC for recording / reproducing control is formed on the surface of the suspension on the side where the head slider is mounted, and an opening for leading the wiring pattern to the surface on the opposite side of the suspension is formed. Formed, bent the wiring pattern on the back surface of the suspension, connected to the bent portion on the back surface of the suspension, mounted a preamplifier IC chip, injected resin into the preamplifier IC surface through the opening, and sealed the preamplifier IC surface. A method for mounting a preamplifier IC.