Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
2001-03-15
2004-11-30
Korzuch, William (Department: 2653)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
Reexamination Certificate
active
06826016
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2000-085424, filed Mar. 24, 2000, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
The present invention relates to a head suspension assembly (hereinafter abbreviated as a HSA) and particularly to a HSA mounting a head IC together with a magnetic head, and a magnetic disk apparatus comprising the HSA.
In general, a magnetic disk apparatus comprises a magnetic disk, a spindle motor for supporting, rotating the magnetic disk, a carriage assembly for supporting and driving a magnetic head, a voice coil motor for driving the carriage assembly, and a main flexible printed circuit board (hereinafter called as a main FPC) for electrically connecting the magnetic head to a control section, which are arranged in a case.
The carriage assembly includes a bearing unit attached to the case, and a plurality of HSAs extending from the bearing unit. The magnetic head is mounted on the extended end portion of each HSA. This HSA has an arm made of a thin metal plate spring and having a proximal end portion which is supported on the bearing unit, an elongate suspension extending from the distal end of the arm and supporting the magnetic head on its distal end portion, and an elongate trace adhered on the suspension and arm. The magnetic head is connected to the main FPC through the trace. This trace is constructed by layering a relay flexible printed circuit board on a thin metal lined plate, for example, made of stainless or the like.
The main FPC has a connection end portion fixed on the bearing unit by a screw, and a proximal end portion connected to the control circuit board fixed to the case. Also, the main FPC has a plurality of connection pads provided at the connection end portion, and a plurality of wiring patterns extending from these connection pads to the proximal end portion. Further, the proximal end portion of the trace extending from the magnetic heads is soldered on the connection pads provided at the connection end portion of the main FPC. In this manner, the magnetic heads are electrically connected to the control circuit board and controlled by this control circuit board.
Meanwhile, the head IC (signal processing IC, integrated circuit element) which amplifies a signal read from the magnetic recording medium by the magnetic head is generally equipped on the control circuit board. In contrast, recently, the length of each wiring pattern from the magnetic head to the head IC can be shortened so that the inductances and capacitances of the wiring patterns can be reduced by mounting the head IC on the trace of the HSA near the magnetic head, as shown in Japanese Patent Application KOKAI Publication No. 11-213365, for example. In addition, a proposal has been made for a HSA equipped with a capacitor (capacitor element) for smoothening the power source.
If the head IC is thus equipped on the HSA, total five wiring patterns, i.e., two signal lines, two power lines (Vcc and Vee), and one ground line (GND) are formed on the trace.
Meanwhile, in the main FPC connected with the trace, independent five wiring patterns are provided in correspondence with one trace. Therefore, for example, the main FPC in a magnetic disk apparatus comprising four HSAs has twenty independent wiring patterns and two wiring patterns for VCM, so that the entire width of the main FPC becomes large. Further, this main FPC constructs a movable part which shifts in accordance with rotation of the head actuator. Therefore, if the width is increased, the main FPC undesirably causes a resistance when the head actuator moves.
Also, the FPC forming part of the trace has a structure in which wiring patterns made of copper foil are sandwiched between insulation layers made of polyimide or the like. Further, the wiring patterns of the FPC which is electrically connected with the head IC are covered with insulation layers, a lining plate having a low heat conductivity, and a suspension, so that only poor heat radiation is attained. Therefore, it is difficult to radiate efficiently heat generated from the head IC, and the temperature of the head IC may exceed a guaranteed temperature range. Further, heat from the head IC transfers to the magnetic head so that the characteristics of the magnetic head change, and the lining plate of the trace and the suspension may thermally expand thereby changing the characteristics of the entire HSA.
In addition, if circuits in the head IC that generate heat of high calorie are not provided symmetrically in the right and left sides with respect to the center line of the HSA, thermal expansion is not symmetrical between the left and right sides in the part which supports the magnetic head of the suspension. Consequently, the characteristics of the magnetic head may be deteriorated.
If the head IC and the capacitor are installed on the HSA, the capacitor cannot be thinned more than the head IC because of its structure, and therefore, the capacitor may contact the magnetic disk surface when the magnetic disk apparatus receives an impact or the like and is deformed thereby.
BRIEF SUMMARY OF THE INVENTION
The present invention has been made in view of the above circumstances, and has an object of providing a head suspension assembly capable of reducing influences from heat of the head IC and maintaining excellent characteristics and a magnetic disk apparatus comprising the head suspension assembly.
The present invention has another object of providing a head suspension assembly on which a capacitor can be installed without damaging the magnetic disk and a magnetic disk apparatus comprising the same.
The present invention further has another object of providing a magnetic disk apparatus capable of reducing the number of wiring lines of the main FPC and of reducing thereby the entire width.
To achieve the above objects, a head suspension assembly according to the present invention comprises: a suspension having a distal end portion on which a magnetic head is mounted; a flexible printed circuit board arranged on the suspension with a lining plate interposed therebetween; and a head IC mounted on the flexible printed circuit board and positioned near the magnetic head. The flexible printed circuit board includes a first wiring pattern which electrically connects the magnetic head with the head IC, a second wiring pattern which extends from the head IC to a proximal end portion of the suspension, and insulation films which cover the first and second wiring patterns from both sides, and the insulation films are removed from an area which faces the head IC, and the lining plate and the suspension has an opening in the area which faces the head IC such that the first and second wiring patterns are exposed through the opening.
Also, according to another head suspension assembly of the present invention, the flexible printed circuit board includes a first wiring pattern which electrically connects the magnetic head with the head IC, a second wiring pattern which extends from the head IC to a base end side of the suspension, and insulation films which cover the wiring patterns from both sides. The insulation films are removed from an area which faces the head IC, and the lining plate and the suspension has an opening at the area which faces the head IC. A heat radiation member is provided in the opening, kept in contact with the wiring patterns.
Further, another head suspension assembly according to the present invention comprises: a suspension having a distal end portion on which a magnetic head is mounted; a flexible printed circuit board installed on the suspension with a lining plate interposed therebetween; a head IC mounted on the flexible printed circuit board and positioned near the magnetic head; and a heat radiation member covering an outer surface of the head IC.
According to the head actuator assemblies having the above mentioned construction, the heat radiation efficiency of the head IC is impr
Kabushiki Kaisha Toshiba
Korzuch William
Magee C R
Pillsbury & Winthrop LLP
LandOfFree
Head suspension assembly and magnetic disk apparatus... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Head suspension assembly and magnetic disk apparatus..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Head suspension assembly and magnetic disk apparatus... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3354881