US20010016975A1 - Method for assembling a magnetic head assembly and magnetic disk drive using bonding balls connecting magnetic head terminals to wiring terminals - Google Patents
Method for assembling a magnetic head assembly and magnetic disk drive using bonding balls connecting magnetic head terminals to wiring terminals Download PDFInfo
- Publication number
- US20010016975A1 US20010016975A1 US09/107,010 US10701098A US2001016975A1 US 20010016975 A1 US20010016975 A1 US 20010016975A1 US 10701098 A US10701098 A US 10701098A US 2001016975 A1 US2001016975 A1 US 2001016975A1
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- United States
- Prior art keywords
- magnetic head
- slider
- suspension
- gimbal
- magnetic
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- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
- G11B5/4853—Constructional details of the electrical connection between head and arm
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B21/00—Head arrangements not specific to the method of recording or reproducing
- G11B21/16—Supporting the heads; Supporting the sockets for plug-in heads
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/012—Recording on, or reproducing or erasing from, magnetic disks
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/1278—Structure or manufacture of heads, e.g. inductive specially adapted for magnetisations perpendicular to the surface of the record carrier
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/127—Structure or manufacture of heads, e.g. inductive
- G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
- G11B5/3103—Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
- G11B5/4826—Mounting, aligning or attachment of the transducer head relative to the arm assembly, e.g. slider holding members, gimbals, adhesive
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
- G11B5/4833—Structure of the arm assembly, e.g. load beams, flexures, parts of the arm adapted for controlling vertical force on the head
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
- G11B5/484—Integrated arm assemblies, e.g. formed by material deposition or by etching from single piece of metal or by lamination of materials forming a single arm/suspension/head unit
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
- G11B5/486—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives with provision for mounting or arranging electrical conducting means or circuits on or along the arm assembly
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- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/488—Disposition of heads
- G11B5/4886—Disposition of heads relative to rotating disc
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
- G11B5/58—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed with provision for moving the head for the purpose of maintaining alignment of the head relative to the record carrier during transducing operation, e.g. to compensate for surface irregularities of the latter or for track following
- G11B5/60—Fluid-dynamic spacing of heads from record-carriers
- G11B5/6005—Specially adapted for spacing from a rotating disc using a fluid cushion
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49025—Making disc drive
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49027—Mounting preformed head/core onto other structure
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49027—Mounting preformed head/core onto other structure
- Y10T29/4903—Mounting preformed head/core onto other structure with bonding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
- Y10T29/00—Metal working
- Y10T29/49—Method of mechanical manufacture
- Y10T29/49002—Electrical device making
- Y10T29/4902—Electromagnet, transformer or inductor
- Y10T29/49021—Magnetic recording reproducing transducer [e.g., tape head, core, etc.]
- Y10T29/49032—Fabricating head structure or component thereof
Definitions
- the present invention relates to a magnetic head assembly having a thin-film or MR type magnetic head used for a magnetic disk drive.
- FIG. 1A is an exploded view of an example of a magnetic head assembly (which can also be referred to as a magnetic head suspension unit) having a thin-film type magnetic head used for the conventional magnetic disk drives.
- FIG. 1B is an exploded view of a part of the magnetic head suspension unit shown in FIG. 1A.
- the magnetic head suspension unit refers to an assembly of a spring arm having a magnetic head mounted on an end of the spring arm. The other end of the spring arm is adapted to be mounted on a member of a magnetic head positioning mechanism.
- one end (a base portion 1 a ) of a spring arm (suspension) 1 formed of an elastic plate is mounted to a member of a magnetic head positioning mechanism (not shown in the figure) via a plate-like spacer 2 .
- a gimbal 3 is mounted on another end 1 b of the spring arm 1 .
- the gimbal 3 is mounted, as shown in FIG. 1B, on the spring arm 1 by means of laser welding at positions indicated by x.
- a core slider (head slider) 4 of a magnetic head h is mounted by adhesive on the gimbal 3 .
- Two magnetic head elements 5 are formed on a rear side surface of the magnetic head, the magnetic head elements 5 being connected by lead wires 6 which lead to a read wire 8 covered with an insulating tube 7 fixed to the spring arm 1 .
- the lead wire 8 is lead to a recording/reproducing circuit 9 shown in FIG. 2.
- the spring arm 1 is slightly bent near the base portion 1 a so that a bent portion 1 c is formed so as to generate a spring force.
- FIG. 2 is an exploded view of a conventional magnetic disk drive in which two magnetic head suspension units shown in FIG. 1A are used.
- Two magnetic head suspension units are mounted on a driving arm 13 which pivots about an axis 12 so that a magnetic disk 10 accommodated inside the magnetic head drive is sandwiched between two of the core sliders 4 mounted on the respective spring arms 1 .
- Each of the core sliders 4 is pressed to a respective surface of the magnetic disk 10 by the spring force generated by the bent portion 1 c.
- the magnetic heads h When the magnetic disk 10 is rotated at a high speed, the magnetic heads h float, if the magnetic heads h are of the floating type, on the respective surface of the magnetic disk 10 due to an air flow generated by the rotation of the magnetic disk 10 . If the magnetic heads h are contact type magnetic heads, the magnetic heads h do not float, but instead slide on the respective surfaces of the magnetic disk 10 . The magnetic heads h are moved to respective target tracks on the surfaces of the magnetic disk 10 by pivoting the spring arms about the axis 12 .
- FIG. 3 is a perspective view of a thin-film type magnetic head.
- FIG. 4 is an enlarged cross sectional view of the thin-film type magnetic head shown in FIG. 3 taken along a line A-A of FIG. 3.
- the thin-film type magnetic head shown in FIG. 3 comprises the slider 4 and head elements 5 .
- the head elements 5 are formed by means of a film deposition technique and lithography.
- Terminals 15 a and 15 b for recording/reproducing coils are provided near the head elements 5 .
- Each of the head elements 5 comprises a lower magnetic pole 16 , an upper magnetic pole 17 and a thin-film coil 19 wound around a connecting portion 18 between the lower magnetic pole 16 and the upper magnetic pole 17 .
- a gap insulating layer 20 is provided between the lower magnetic pole 16 and the upper magnetic pole 17 so that a gap G having a predetermined width is formed between the two poles.
- the gap G faces the surface of the magnetic disk 10 to perform an magnetic recording/reproducing operation.
- the insulating tube 7 occupies a relatively large space to prevent miniaturization of the magnetic disk drive. Additionally, the insulating tube 7 makes an assembling operation difficult, particularly an automated assembling operation. Further, there is a strong possibility that the lead wire 8 will pick up noises, resulting in degradation of an S/N ratio of a signal sent via the lead wire 8 .
- a method for forming a signal transmitting line on a spring arm is suggested in Japanese Laid-Open Patent Application No.4-21918.
- a signal line is formed of a pattern of a conductive layer on an insulating layer formed on the spring arm.
- the method has a problem in that the signal transmitting line formed of the conductive layer is easily damaged or broken during a process for forming the bent portion 1 c shown in FIG. 1A.
- Japanese Laid-Open Patent Application No.4-111217 discloses a magnetic head suspension unit in which a flexible printed circuit board is attached to a spring arm, and a portion of the flexible circuit board corresponding to the above of the spring arm bent portion is not adhered to the spring arm. Instead, in this construction, the portion of the flexible printed circuit board corresponding to the bent portion of the spring arm is free, and thus the there is no bending stress applied to the flexible printed circuit board.
- this construction cannot be applied to a highly miniaturized spring arm such as a spring arm having a thickness of a few microns and a 4.6 mm width.
- the insulation between the thin-film coil 19 and the poles 16 or 17 is damaged, an electric discharge may occur between the core slider, which is made of a conductive material such as Al 2 O 3 TiC, and the magnetic poles 16 or 17 , resulting in the gap G or the floating surface of the core slider 4 being damaged. Additionally, when the magnetic disk drive is in operation, an electric discharge may occur between the magnetic disk 10 and the magnetic poles 16 or 17 , resulting in the magnetic gap G being damaged.
- the core slider 4 is damaged, the floating characteristic of the magnetic head is deteriorated, which condition causes a generation of noises in the recording/reproducing signal. If the magnetic head is a contact type head, the damaged surface of the magnetic head may scratch the magnetic disk 10 .
- a more specific object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which damaging of a conductive-pattern layer formed on a spring arm during a process of bending the spring arm can be prevented.
- Another object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which no insulation breakage occurs due to generation of static electricity.
- Another object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which thermal deformation of a slider core is prevented.
- a magnetic head assembly comprising:
- the magnetic head assembly may be configured so that the balls are made of gold.
- the magnetic head assembly may be configured so that the terminals of the wiring lines are provided on the gimbal portion.
- the magnetic head assembly may be configured so that the wiring lines are formed by a wiring pattern.
- the magnetic head assembly may be configured so that the slider is provided on a surface of the gimbal portion on which the wiring lines are provided.
- the magnetic head assembly may be configured so that the slider is provided on the gimbal portion so that the terminals of the wiring pattern and the terminals of the slider face each other in an orthogonal formation.
- the magnetic head assembly may be configured so that the gimbal portion is a part of a suspension so that the gimbal portion is integrally formed with the suspension.
- the magnetic head assembly may be configured so that the wiring lines are formed by a wiring pattern formed on the suspension.
- the magnetic head assembly may be configured so that the slider is provided on a surface of the gimbal portion on which the wiring lines are provided.
- the magnetic head assembly may be configured so that the slider is provided on the gimbal portion so that the terminals of the wiring pattern and the terminals of the slider face each other in an orthogonal formation.
- a magnetic disk drive comprising:
- FIG. 1A is an exploded view of an example of a magnetic head assembly having the thin-film type magnetic head used for the conventional magnetic disk drives;
- FIG. 1B is an exploded view of a part of the magnetic head assembly shown in FIG. 1A;
- FIG. 2 is an exploded view of a conventional magnetic disk drive in which two magnetic head assemblies shown in FIG. 1A are used;
- FIG. 3 is a perspective view of a thin-film type magnetic head
- FIG. 4 is an enlarged cross sectional view of the thin-film type magnetic head shown in FIG. 3 taken along a line A-A of FIG. 3;
- FIG. 5A is a perspective view of a first embodiment of a magnetic head assembly according to the present invention.
- FIG. 5B is an enlarged cross sectional view taken along a line b-b of FIG. 5A;
- FIG. 6A is a perspective view of the spring arm shown in FIG. 5A in a state where a magnetic head has not been mounted on a gimbal;
- FIG. 6B is an illustration showing a process for forming conductive-pattern layers on the spring arm
- FIGS. 7A through 7C are illustrations showing a process for bending the bent portions shown in FIG. 6A;
- FIG. 8A is a perspective view of a second embodiment of a magnetic head assembly according to the present invention.
- FIG. 8B is an enlarged partial cross sectional view taken along a line b-b of FIG. 8A;
- FIG. 8C is an enlarged partial cross sectional view taken along a line c-c of FIG. 8A;
- FIG. 8D is a partial cross sectional view of a variation of the spring arm shown in FIG. 8A;
- FIG. 9A is a perspective view of a third embodiment of a magnetic head assembly according to the present invention.
- FIG. 9B is a cross sectional view taken along a line b-b of FIG. 9A;
- FIG. 10 is a perspective view of a fourth embodiment of a magnetic head assembly according to the present invention.
- FIG. 11A is a perspective view of a fifth embodiment of a magnetic head assembly according to the present invention.
- FIG. 11B is an enlarged partial cross sectional view taken along a line b-b of FIG. 11A.
- FIG. 12A is a perspective view of a sixth embodiment of a magnetic head assembly according to the preset invention.
- FIG. 12B is an enlarged partial cross sectional view taken along a line b-b of FIG. 12A;
- FIG. 12C is an enlarged partial cross sectional view taken along a line c-c of FIG. 12C;
- FIG. 13A is a perspective view of a seventh embodiment of a magnetic head assembly according to the present invention.
- FIG. 13B is a variation of the embodiment shown in FIG. 13A;
- FIG. 14 is a perspective view of an eighth embodiment of a magnetic head assembly according to the present invention.
- FIG. 15A is a perspective view of the magnetic head shown in FIG. 14;
- FIG. 15B is a cross sectional view taken along a line b-b of FIG. 15A;
- FIG. 16 is an exploded view of an essential part of a ninth embodiment of a magnetic head assembly according to the present invention.
- FIG. 17 is an exploded view of an essential part of a variation of the ninth embodiment shown in FIG. 16;
- FIG. 18 is a perspective view of an essential part of a tenth embodiment of a magnetic head assembly according to the present invention.
- FIG. 19 is an exploded view of an eleventh embodiment of a magnetic head assembly according to the present invention.
- FIG. 20A is a perspective view of a spring arm of a twelfth embodiment of a magnetic head assembly according to the present invention.
- FIG. 20B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 20A;
- FIGS. 21A through 21F are illustrations of variations of the hole shown in FIG. 20A.
- FIG. 22A is a perspective view of a spring arm of a thirteenth embodiment of a magnetic head assembly according to the present invention.
- FIG. 22B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 22A;
- FIG. 22C is an enlarged cross sectional view showing a variation of the mounting structure shown in FIG. 22B;
- FIG. 23 is a perspective view of a magnetic head assembly according to a fourteenth embodiment of the present invention.
- FIG. 24 is a plan view of a 3.5-inch magnetic disk drive to which the magnetic head assembly shown in FIG. 23 is applied;
- FIG. 25 is a perspective view of a first-order bend state of a suspension shown in FIG. 23;
- FIG. 26 is a perspective view of a first-order twist state of the suspension shown in FIG. 23;
- FIG. 27 is a perspective view of the upper side of the magnetic head assembly shown in FIG. 23;
- FIG. 28 is a side view of the magnetic head assembly shown in FIG. 23;
- FIG. 29 is a perspective view of a magnetic head assembly according to a fifteenth embodiment of the present invention.
- FIG. 30 is a perspective view of a magnetic head assembly according to a sixteenth embodiment of the present invention.
- FIG. 31 is a perspective view of a magnetic head assembly according to the twelfth embodiment of the present invention.
- FIG. 32 is a side view of the mechanism shown in FIG. 31;
- FIG. 33 is a perspective view of a magnetic head assembly according to an eighteenth embodiment of the present invention.
- FIG. 34 is a perspective view of a magnetic head assembly according to a nineteenth embodiment of the present invention.
- FIG. 35 is a plan view of a free-end part of a suspension shown in FIG. 34;
- FIG. 36 is a sectional-view taken along a line XIV-XIV shown in FIG. 34;
- FIG. 37 is a perspective view of a magnetic head slider shown in FIG. 34;
- FIG. 38 is a flowchart of a production process for the suspension shown in FIG. 34;
- FIG. 39 is a plan view of a plate obtained after an etching step shown in FIG. 38 is carried out;
- FIG. 40 is a flowchart of another production process for the suspension shown in FIG. 34;
- FIG. 41 is a perspective view of a variation of the nineteenth embodiment of the present invention.
- FIG. 42 is a perspective view of a magnetic head assembly according to a twelfth embodiment of the present invention.
- FIG. 43 is a plan view of a magnetic disk drive to which the magnetic head assembly shown in FIG. 42 is applied;
- FIGS. 44A and 44B are respectively plan and side views of the magnetic head assembly shown in FIG. 42;
- FIG. 45 is a side view of a state observed when the magnetic head assembly shown in FIG. 42 is provided in the magnetic disk drive;
- FIG. 46 is an emphasized view of the state in FIG. 45;
- FIG. 47 is a side view of a first-order bend state of a suspension used in the twelfth embodiment of the present invention.
- FIG. 48 is a side view of a first-order twist state of the suspension used in the twelfth embodiment of the present invention.
- FIG. 49 is a plan view of a first variation of a gimbal of the suspension used in the twelfth embodiment of the present invention.
- FIG. 50 is a plan view of a second variation of the gimbal of the suspension used in the twelfth embodiment of the present invention.
- FIG. 51 is a plan view of a third variation of the gimbal of the suspension used in the twelfth embodiment of the present invention.
- FIG. 52 is a plan view of a fourth variation of the gimbal of the suspension used in the twelfth embodiment of the present invention.
- FIG. 53 is a plan view of a fifth variation of the gimbal of the suspension used in the twelfth embodiment of the present invention.
- FIG. 54 is a side view of a variation of the twelfth embodiment of the present invention.
- FIG. 55 is a top view of another embodiment of a magnetic disk apparatus of the present invention.
- FIG. 56 is a cross section of the magnetic disk apparatus in FIG. 55;
- FIG. 57 is a top view of an actuator in FIG. 55;
- FIG. 58 is a perspective view of a magnetic head assembly according to a further embodiment of the present invention.
- FIG. 59 illustrates another connecting mechanism of the magnetic head assembly in FIG. 58;
- FIG. 5A is a perspective view of a first embodiment of a magnetic head assembly according to the present invention
- FIG. 5B is an enlarged cross sectional view taken along a line b-b of FIG. 5A.
- the magnetic head assembly is also referred to a magnetic head suspension unit or merely suspension unit.
- FIGS. 5A and 5B parts that are the same as the parts shown in FIG. 1A are given the same reference numerals, and descriptions thereof will be omitted.
- the first embodiment according to the present invention comprises the spring arm 1 and the slider core 4 of the magnetic head.
- a gimbal 24 supported by bridge portions 23 a and 23 b is formed on the end 1 b of the spring arm 1 .
- the core slider (head slider) 4 of the magnetic head is mounted on the gimbal 24 by an adhesive which has an insulation effect and can be an insulation adhesive or an adhesive containing an insulator.
- the insulation adhesive is an insulator in which the insulator itself has the insulation effect.
- the base portion (attachment portion) 1 a of the spring arm 1 is fixed to a member of a magnetic head positioning mechanism.
- Conductive-pattern layers 25 run from the base portion la to the gimbal 24 so as to transmit signals to/from the magnetic head.
- FIG. 6A is a perspective view of the spring arm 1 shown in FIG. 5A in a state where the magnetic head has not been mounted on the gimbal 24 .
- a portion of the core slider 4 is also shown to explain electrical connection between the magnetic head and the conductive-pattern layers 25 .
- a pad 25 a is formed at the end of each of the two conductive-pattern layers 25 .
- the core slider of the magnetic head is also provided with pads 26 . When the core slider 4 is mounted on the gimbal 24 , the pads 26 make contact with the respective pads 25 a. The pads 26 and the pads 25 a are then soldered together to assure an electric connection.
- the core slider 4 in FIG. 6A is viewed from a direction indicated by an arrow B of FIG. 5A.
- the conductive-pattern layers 25 on the spring arm 1 are formed by a process shown in FIG. 6B.
- an insulating layer 27 is formed on the spring arm 1 by applying a polyimide resin over the spring arm 1 made of stainless steel.
- the thickness of the spring arm 1 is about 25 ⁇ m, and the thickness of the insulating layer 27 is 3-4 ⁇ m.
- a base layer 28 is then formed on the insulating layer 27 , as shown in FIG. 6B- 3 , by sputtering copper (Cu) onto the insulating layer 27 .
- the base layer 28 may instead be formed by vapor deposition or chemical plating.
- rectangular holes 31 a and 31 b are formed on the spring arm 1 , as shown in FIG. 5A, on either side of the conductive-pattern layers 25 .
- the rectangular holes 31 a and 31 b separate a portion of the spring arm 1 , on which the conductive-pattern layers 25 are formed, from bent portions 33 a and 33 b to which a pressing force is applied to bend the spring arm 1 .
- the rectangular holes 31 a and 31 b may instead be slits 32 a and 32 b as shown in FIG. 6A.
- FIGS. 7A through 7C are illustrations showing a process for bending the bent portions 33 a and 33 b.
- a roller 34 having larger diameter portions 35 a and 35 b is prepared.
- the larger diameter portions 35 a and 35 b bends the corresponding bent portions 33 a and 33 b.
- the bent portions 33 a and 33 b which are formed as an elastic portion R generating an elastic force, of spring arm 1 are placed on a rubber table 36 .
- the roller 34 is then rolled, as shown in FIG. 7B, on the bent portion 33 a and 33 b while it is being pressed.
- the roller 34 is not pressed on the portion where the conductive-pattern layers 25 have been formed, and thus no damage to the conductive-pattern layers 25 occurs.
- FIG. 8A is a perspective view of a second embodiment of a magnetic head suspension unit according to the present invention
- FIG. 8B is an enlarged partial cross sectional view taken along a line b-b of FIG. 8A
- FIG. 8C is an enlarged partial cross sectional view taken along a line c-c of FIG. 8A
- FIG. 8D is a partial cross sectional view of a variation of the spring arm shown in FIG. 8A.
- a recessed portion 39 is formed in the elastic portion R where an elastic force is generated.
- the conductive-pattern layers 25 are formed in the recessed portion 39 .
- the recessed portion 39 covers an entire length C of the elastic portion R and a width B so as to cover the portions of the conductive-pattern layers 25 located in the elastic portion R of the spring arm 1 .
- a portion of the insulating layer 27 shown in FIG. 6B- 2 is formed also inside the recessed portion 39 .
- the base layer 28 and the copper layer 29 are then formed on the entire surface of the insulating layer 27 including the portion thereof inside the recessed portion 39 so as to form the conductive-pattern layers 25 .
- the insulating layer 30 is formed on the conductive-pattern layers 25 so that a top surface of the insulating layer 30 located inside the recessed portion 39 is below the surface of the spring arm 1 as shown in FIG. 8B.
- the recessed portion 39 is formed by means of etching
- the recessed portion 39 may instead be formed by means of press forming as shown in FIG. 8D.
- press forming the recessed portion 39 can be formed even if the thickness of the spring arm 1 is very slight or the total thickness of the insulating layers 27 and 30 and the conductive-pattern layers 25 is great.
- the recessed portion 39 may be formed so that an entire length 25 L of straight portions of the conductive-pattern layers 25 is embedded in the recessed portion 39 .
- FIG. 9A is a perspective view of a third embodiment of a magnetic head suspension unit according to the present invention
- FIG. 9B is a cross sectional view taken along a line b-b of FIG. 9A.
- portions 25 r of the conductive-pattern layers 25 are wider than other portions of the conductive-pattern layers 25 . That is, a width C 1 of each of the portion 25 r of the conductive-pattern layers 25 within the elastic portion R is widened over a length L corresponding to the elastic portion R.
- the total thickness of the conductive-pattern layers 25 and insulating layers 27 and 30 is uniform over the entire width of the widened portions 25 r of the conductive-pattern layers 25 .
- a roller 35 having a straight cylindrical surface is pressed over the entire width of the elastic portion R so as to bend the elastic portion R.
- the pressing force exerted by the roller 35 is concentrated onto the conductive-pattern layers 25 .
- the pressing force is dispersed onto the entire width of the widened conductive-pattern layers 25 , and thus damage or breakage of the conductive-pattern layers 25 is prevented. Additionally, even if damage such as a cracking of portions of the conductive-pattern layers 25 occurs, other portions of the layers 25 which are not damaged, resulting in reliable electric continuity.
- the width c 1 of each of the portion 25 r of the conductive-pattern layers 25 is 2.0 mm, and the length L is 1.5 mm.
- FIG. 10 is a perspective view of a fourth embodiment of a magnetic head suspension unit according to the present invention.
- zigzagging conductive-pattern portions 25 z of the conductive-pattern layers 25 within the elastic portion R are formed to extend in a direction oblique to a direction in which other portions of the conductive-pattern layers 25 extend.
- U-turn portions 25 c are formed with a width greater than other portions.
- FIG. 11A is a perspective view of a fourth embodiment of a magnetic head suspension unit according to the present invention
- FIG. 11B is an enlarged partial cross sectional view taken along a line b-b of FIG. 11A.
- a plurality of dummy patterns 25 d are formed within the elastic portion R.
- the dummy patterns 25 d have the same construction as the conductive-pattern layers 25 .
- the pressing force is dispersed onto the dummy patterns 25 d, and thus damage and breakage of the conductive-pattern layers 25 is prevented unlike in the case of the conventional conductive-pattern layers in which the pressing force is concentrated onto the conductive-pattern layers.
- FIG. 12A is a perspective view of a sixth embodiment of a magnetic head suspension unit according to the preset invention
- FIG. 12B is an enlarged partial cross sectional view taken along a line b-b of FIG. 12A
- FIG. 12C is an enlarged partial cross sectional view taken along a line c-c of FIG. 12C.
- a protecting layer is formed over portions of the conductive-pattern layers 25 in the elastic portion R.
- the protecting layer comprises a conducting layer 37 and an insulating layer 38 .
- a copper base layer is formed on the insulating layer 30 in the process shown in FIG. 6B- 3 - 6 .
- the conductive layer 37 made of copper is then formed by means of electro plating, and the layer 37 is patterned.
- Polyimide resin is coated over the conductive layer 37 so as to form the insulating layer 38 .
- the insulating layer 30 formed over the conductive-pattern layers 25 is formed with a relatively great thickness so that the insulating layer 30 can be flattened and smoothed by means of surface polishing.
- the conductive layer 37 has a relatively large width B to cover the conductive-pattern layers 25 , and has a length C which covers the length of the elastic portion R as shown in FIG. 12A.
- the roller 35 exerts a pressing force onto the conductive layer 37 which has a relatively high strength, and thus the pressing force is uniformly dispersed onto the conductive layer 37 . Accordingly, damage to the conductive-pattern layers 25 is prevented when the spring arm 1 is bent by the roller 35 .
- FIG. 13A is a perspective view of a seventh embodiment of a magnetic head suspension unit according to the present invention.
- extra conductive-pattern layers 25 s are formed.
- the extra conductive-pattern layers 25 s are formed along each of the conductive layers 25 .
- Both ends of each of the additional conductive-pattern layers 25 s are connected to the ends of the respective conductive-pattern layers 25 at corresponding connection parts 40 and 41 . Accordingly, if one of the conductive-pattern layers 25 is damaged to lose continuity, the corresponding extra conductive-pattern layer 25 s serves the same function as the damaged conductive-pattern layer 25 . Therefore, a reliable connection can be realized.
- FIG. 13B is a variation of the seventh embodiment according to the present invention.
- each of the conductive-pattern layers 25 has two paths along the straight portion thereof within the elastic portion R. One of the paths serves as the extra conductive-pattern layer 25 s.
- bent portions are formed by a press method using a roller, other method using a mold press or laser may be used.
- the spring arm 1 Since the spring arm 1 according to the above-mentioned embodiments is mounted on a member of the magnetic head positioning mechanism, as shown in FIG. 2, the magnetic disk drive can reliably transmit recording/reproducing signals through the spring arm.
- FIG. 14 is a perspective view of the eighth embodiment of a magnetic head suspension unit according to the present invention.
- FIG. 14 parts that are the same as the parts shown in FIG. 1A are given the same reference numerals, and descriptions thereof will be omitted.
- FIG. 15A is a perspective view of the magnetic head h shown in FIG. 14;
- FIG. 15B is a cross sectional view taken along a line b-b of FIG. 15A.
- the core slider 4 is mounted on the gimbal 3 by adhesive 42 having a high insulating effect.
- the core slider 4 may instead be directly mounted on the end 1 b of the spring arm 1 .
- the core slider is also mounted by adhesive having an insulating effect, the electric resistance between the core slider 4 and the gimbal 3 is low because the adhesive layer is very thin. Accordingly, the core slider 4 may be at the same potential, that is a ground potential, as the spring arm 1 because the spring arm 1 is grounded. If a high voltage static electricity is generated in the thin-film coil of the magnetic head element 5 , the insulating layer between the thin-film coil and the magnetic pole is damaged, resulting in electric discharge between the thin-film coil and the core slider.
- the adhesive 42 in order to obtain a high resistance between the core slider and the gimbal 3 , a thick layer of the adhesive 42 is provided. It is preferable that the adhesive 42 be a UV cure resin (ultra-violet cure type adhesive). Alternatively, epoxy resin may be used. In the present embodiment, as shown in FIG. 15A, the adhesive 42 comprises an insulating material powder 42 b mixed in adhesive medium 42 a. Accordingly, the adhesive 42 can have a high electric resistance, and is formed with a relatively great thickness, and thus the insulation between the core slider 4 and the gimbal 3 is improved.
- UV cure resin ultraviolet cure type adhesive
- epoxy resin may be used.
- the adhesive 42 comprises an insulating material powder 42 b mixed in adhesive medium 42 a. Accordingly, the adhesive 42 can have a high electric resistance, and is formed with a relatively great thickness, and thus the insulation between the core slider 4 and the gimbal 3 is improved.
- FIG. 16 is an exploded view of an essential part of a ninth embodiment of a magnetic head suspension unit according to the present invention.
- the core slider 4 is mounted on the gimbal 3 or the end 1 b of the spring arm 1 via an insulator 43 .
- the insulator 43 is formed by applying insulating resin such as a photoresist onto a surface of the core slider 4 .
- the core slider is mounted on the gimbal 3 by applying adhesive 44 onto the insulator 43 .
- the insulator 43 may be applied onto a mounting surface of the gimbal 3 .
- FIG. 18 is a perspective view of an essential part of a tenth embodiment according to the present invention.
- a magnetic head comprising the magnetic head elements 5 and a core slider 4 i is shown.
- the core slider 4 i is made of an insulating material such as SiO 2 . Accordingly, the discharge as described in relation to the conventional magnetic head can be eliminated.
- FIG. 19 is an exploded view of an eleventh embodiment of a magnetic head suspension unit according to the present invention.
- the magnetic head suspension unit is mounted on a driving arm 13 of the magnetic head driving mechanism via an insulating member 45 .
- the insulating member has screw holes 46 into which screws for fastening the magnetic head suspension unit to the driving arm 13 are inserted.
- the screws are made of synthetic resin or metal screws covered with synthetic resin.
- the spring arm 1 is insulated from the driving arm 13 , which may be grounded.
- the spacer 2 may be made of an insulating material.
- FIG. 20A is a perspective view of a spring arm of a twelfth embodiment of a magnetic head suspension unit according to the present invention
- FIG. 20B is an enlarged cross sectional view showing a mounting structure of the core slider shown in FIG. 20A.
- a gimbal 24 formed on the spring arm 1 has a hole 47 in the center thereof.
- the core slider 4 is mounted on the gimbal 24 by adhesive 48 so that the hole 47 is filled with the adhesive 48 .
- the gimbal can be easily bent, if bending stress is applied to the gimbal 24 due to a difference in thermal expansion between the core slider and the gimbal 24 . Accordingly, bending stress applied to the core slider 4 is reduced since the gimbal 24 is bent instead of the core slider 4 . This feature is important when a thin and miniaturized core slider is used.
- FIGS. 21A through 21F Variations of the hole 47 are shown in FIGS. 21A through 21F.
- a plurality of holes 47 may be provided, and each hole may have a rectangular shape.
- the hole 47 is filled with a part of the adhesive applied between the core slider 4 and the gimbal 24 , so that the strength of the adhesion between the core slider 4 and the gimbal 24 is increased. Additionally, if the UV cure resin is used, an ultra-violet beam can be irradiated through the hole 47 , which effectively cures the UV cure resin, and thus the strength of the cured UV cure resin can be improved.
- the gimbal 24 is integrally formed with the spring arm 1 , the gimbal 24 may be formed separately from the spring arm 1 ; that is, it may be fixed to the spring arm 1 by means of welding described in regard to the conventional magnetic head suspension unit shown in FIG. 1B.
- FIG. 22A is a perspective view of a spring arm of a thirteenth embodiment of a magnetic head suspension unit according to the present invention
- FIG. 22B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 22A
- FIG. 22C is an enlarged cross sectional view showing a variation of the mounting structure shown in FIG. 22B.
- an opening 49 is provided in the gimbal 24 , into which opening the core slider is inserted.
- the opening 49 is slightly larger than the outer dimension of the core slider 4 .
- the core slider 4 is mounted in a state where side faces of the slider core 4 is fixed, as shown in FIG. 22B, by adhesive 50 to the outer edge of the opening 49 .
- the core slider 4 may be formed to have a step in its side surface so that dimension L 2 is larger than dimension L 1 .
- the dimension of the opening is determined to be a value between L 1 and L 2 .
- the adhesive such as UV cure resin is applied to the outer edge of the opening after the core slider 4 is inserted into the opening 49 .
- An ultra-violet beam is, then irradiated from a direction indicated by an arrow in FIG. 22C so as to cure the UV cure resin.
- the magnetic heads shown in FIGS. 20A and 22A are formed with an MR element formed by means of thin-film technology. Thin-film type magnetic head elements are formed on the MR element.
- the present invention is not limited to the specific magnetic head, and a conventional thin-film type magnetic head or a monolithic type magnetic head may be used.
- FIG. 24 shows a 3.5-inch type magnetic disk drive 1220 to which the magnetic head suspension unit 120 is applied.
- the magnetic disk drive 1220 has an enclosure 1221 in which a 3.5-inch magnetic disk 1222 , a head positioning actuator 1223 and other parts are housed.
- a suspension (load beam) 121 made of stainless steel is fixed to an arm 122 of the actuator 223 .
- the suspension 121 has a curved bent portion 123 generating elasticity.
- the curved portion 123 of the suspension 121 is also referred to as an elastic portion 123 in the following description.
- the suspension 121 has a stiffness portion 24 extending from the elastic portion 123 , and ribs 121 a.
- the elastic portion 123 provides a magnetic head slider (core slider) 135 with a load in a direction in which the magnetic head slider 135 moves and comes into contact with a magnetic disk 1222 .
- the suspension 121 has a uniform thickness of, for example, approximately 25 ⁇ m, which is equal to one-third of the thickness of a suspension of a 3380-type (IBM) head suspension unit.
- the width W 1 of the suspension 121 is made as small as possible, desirably 4 mm or less. This is because the resonance frequency of vibration of the suspension 121 is prevented from lowering.
- a gimbal 125 is integrally formed in the suspension 121 so that the suspension 121 and the gimbal has a one-piece construction which uses a plate.
- the gimbal 125 includes a pair of C-shaped openings 126 and 126 facing each other in the longitudinal direction of the suspension 121 .
- Two slits 128 and 129 are formed in the suspension 121 along respective sides of the suspension 121 .
- the gimbal 125 includes a magnetic slider fixing portion 130 , a first pair of beam portions 131 and 132 , and a second pair of beam portions 133 and 134 .
- the magnetic head slider 135 is a light weight structure type slider, which has been proposed in Japanese Patent Laid-Open Application No. 4-228157.
- the proposed slider has a flat back surface opposite to a disk facing surface.
- the flat back surface of the slider is fixed to the fixing portion 130 by means of an adhesive, which can be an insulation adhesive or an adhesive including an insulator (for example, insulator power).
- the slider 135 is located so that the center thereof corresponds to the center of the fixing portion 130 . It is also possible to use other types of sliders.
- the beam portions 131 and 132 extend outwardly from the respective sides of the fixing portion 130 along a line (suspension width direction line) 138 , which passes through the center of the fixing portion 130 (the above center is also the center of the slider 135 ), and crosses a longitudinal center line 137 of the suspension 121 at a right angle.
- Each of the beam portions 131 and 132 has a length 11 .
- the beam portion 133 extends from the beam portion 131 towards the respective sides of the beam portion 131 so that the beam portion 133 crosses the beam portion 131 at a right angle and extends parallel to the line 137 .
- the beam portion 134 extends from the beam portion 132 towards the respective sides of the beam portion 132 so that the beam portion 134 crosses the beam portion 132 at a right angle and extends in parallel with the line 137 .
- the beam portion 133 is joined to portions 140 and 141 of the suspension 121 in the periphery of the gimbal 125 .
- the beam portion 134 is joined to portions 142 and 143 of the suspension 121 in the periphery of the gimbal 125 .
- the beam portion 133 extends from the portions 140 and 141 of the gimbal 125
- the beam portion 134 extends from the portions 142 and 143 of the gimbal 125 .
- the distance between the center of the beam portion 133 and one of the two ends thereof is 1 2 .
- the distance between the center of the beam portion 134 and one of the two ends thereof is also 1 2 .
- the beam portion 133 and the beam portion 131 form a T-shaped beam 139 A.
- the beam portion 134 and the beam portion 132 form a T-shaped beam 139 B.
- the beam portions 131 , 132 , 133 and 134 form an H-shaped beam. It will be noted that the fixing portion 130 , the first pair of beams 131 and 132 , and the second pair of beams 133 and 134 are portions of the suspension 121 .
- the length 1 1 of the first pair of beams 131 and 132 is limited by the width W 1 of the suspension 121 .
- the width W 1 of the suspension 121 As the width W 1 of the suspension 121 is increased, the resonance frequency of a bend and twist of the suspension 121 becomes lower, and the flying characteristics of the slider 135 are degraded. For these reasons, the width W 1 cannot be increased.
- the second pair of beams 133 and 134 is formed so that 1 2 >l 1 . That is, each of the T-shaped beams 39 A and 39 B has a leg portion and an arm portion longer than the leg portion.
- the magnetic head slider 135 is rotated in a pitching direction indicated by an arrow 144 in a state in which the first pair of beams 131 and 132 and the second pair of beams 133 and 134 are bent. At this time, a twist deformation occurs in the first pair of beams 131 and 132 of the gimbal 125 , and a bend deformation occurs in the second pair of beams 133 and 134 .
- the magnetic head slider 135 is rotated in a rolling direction also. At this time, bend deformations occur in the beams 131 and 132 in the respective directions opposite to each other, and bend deformations occur in the beams 133 and 134 in the respective directions opposite to each other.
- FIG. 25 shows a resonance mode of the first-order bend. A deformation occurs in the elastic portion 123 formed at the root of the suspension 121 , and the first pair of beams 131 and 132 and the second pair of beams 133 and 134 are deformed in the same direction.
- FIG. 26 shows a resonance mode of the first-order twist.
- a twist deformation occurs in the elastic portion 123 formed at the root of the suspension 121 in such a manner so the right and left portions of the elastic portion 123 have different heights.
- the beam located on the right side of the gimbal 125 is deformed so as to be formed into a convex shape facing upwards.
- the beam located on the left side of the gimbal 125 is deformed so as to be shaped into a convex facing downwards.
- a composite type magnetic head 148 and four terminals 1100 A, 1100 B, 1100 C and 1100 D are provided in the magnetic head slider 135 .
- the magnetic head 148 includes an MR head for reproduction and an interactive type head for recording, these heads being integrated with each other.
- the magnetic head 148 is located at a rear end surface of the magnetic head slider 135 in a relative movement direction 146 with respect to the magnetic disk 1222 .
- lead wires 115 A, 115 B, 115 C and 115 D are connected to the terminals 1100 A, 1100 B, 1100 C and 1100 D, respectively.
- Each of the lead wires 115 A through 115 D has a diameter of, for example, 30 ⁇ m.
- the lead wires 115 A- 115 D are laid on the side opposite to the side on which the magnetic head slider 135 is mounted, and are attached to a center portion 36 of the fixing portion 130 by means of an adhesive 116 , which can be an insulation adhesive or an insulator containing an insulator. Further, the lead wires 115 A- 115 D extend along the longitudinal center line 137 of the suspension 121 towards the base portion of the suspension 121 , and are fixed thereto at two points by means of the adhesive 116 .
- Reference numbers 117 ⁇ 1 , 117 ⁇ 2 and 117 ⁇ 3 respectively indicate a first fixing point, a second fixing point and a third fixing point at which the lead wires 115 A through 115 D are fixed by means of the adhesive 116 .
- the first fixing point 117 ⁇ 1 moves in accordance with movement of the magnetic head slider 135 .
- the distance between the first fixing point 117 ⁇ 1 and the second fixing point 117 ⁇ 2 is long, and the stiffness of the lead wires 115 A- 115 B between the fixing points 117 ⁇ 1 and 117 ⁇ 2 little affects the rotation stiffness of the gimbal 125 .
- the magnetic head suspension unit 120 has the following features. First, the rotation stiffness of the gimbal 125 is considerably small because of the characteristics of the T-shaped beams. Second, the gimbal 125 is supported at the four points 140 - 143 , and hence, the resonance frequency of vibration of the gimbal 125 is high even when the second pair of beams 133 and 134 is long. Third, the end of the suspension 121 can be formed so that it has a small width W 1 , and hence the resonance frequency of vibration of the suspension 121 is high. Fourth, the flying stability of the magnetic head slider 135 is excellent due to the above first, second and third features.
- the fifth feature of the mechanism 120 is such that the first pair of beams 131 and 132 has a short length l 1 and is formed in the same plane. Hence, the first pair of beams 131 and 132 has a large strength with respect to force received in the contact start/stop operation, and a shear failure does not easily occur in the beams 131 and 132 .
- the sixth feature of the mechanism 120 is such that the stiffness of the lead wires 115 A- 115 D does not affect the rotation stiffness of the gimbal 125 .
- the gimbal 125 is formed so that a pair of T-shaped beams (which form an H-shaped beam) is provided with respect to the center of the gimbal 125 , and hence a low rotation stiffness and a high resonance frequency are achieved. More specifically, the rotation stiffness of the mechanism 120 becomes one-third of that of the aforementioned IBM 3380 type head suspension unit, while the resonance frequency of the mechanism 120 is as high as that of the IBM 3380 type head suspension unit. As a result, it becomes possible to stably fly a compact slider having a low airbearing stiffness.
- Tables 1 and 2 show characteristics of the head suspension unit 120 according to the fourteenth embodiment of the present invention supporting a 2 mm-length slider, and the IBM 3380 type head suspension unit supporting which a 3.2 mm-length slider.
- TABLE 1 COMPARISON OF STIFFNESS (static characteristics by computer simulation) Stiffness 1st embodiment 3380 type pitch stiffness 1.5 grf cm/rad 9.4 grf cm/rad roll stiffness 1.5 grf cm/rad 5.1 grf cm/rad up/down stiffness 0.55 grf/mm 2.4 grf/mm equivalent weight ratio 0.74 0.72
- the total length of the suspension unit is short (10 mm), which is approximately half of that of the IBM 3380 type mechanism.
- the thickness of the suspension 121 of the fourteenth embodiment is 25 ⁇ m, which is approximately one-third of that of the IBM 3380 type mechanism.
- Table 1 shows data obtained by computer simulation. More specifically, Table 1 shows the pitch stiffness and roll stiffness of the gimbal 125 of the fourteenth embodiment, and the up/down stiffness of the suspension 121 thereof. Further, Table 1 shows the pitch stiffness and the roll stiffness of the gimbal of the IBM 3380 type mechanism, and the up/down stiffness of the suspension thereof. It can be seen from Table 1 that the rotation stiffness equal to one-third of the gimbal of the IBM 3380 type mechanism can be obtained by optimizing the width and length of the grooves in the gimbal 125 .
- Table 2 shows the resonance frequencies of the fourteenth embodiment and the conventional IBM 3380 type mechanism obtained by a computer simulation.
- the resonance frequencies of the fourteenth embodiment are similar to those of the IBM 3380 type mechanism.
- the magnetic head suspension unit according to the fourteenth embodiment of the present invention has a low stiffness and a high resonance frequency.
- FIG. 29 shows a magnetic head suspension unit 150 according to the fifteenth embodiment of the present invention.
- the mechanism 150 includes a gimbal 151 .
- the gimbal 151 is formed so that the gimbal 125 shown in FIG. 23 is rotated about the center 136 by 90°.
- Two T-shaped beams 152 and 153 are arranged in the longitudinal direction of the suspension 121 .
- FIG. 30 shows a magnetic head suspension unit 160 having a gimbal 161 according to a sixteenth embodiment of the present invention.
- the gimbal 161 has the aforementioned first pair of beams 131 and 132 , and a second pair of beams 33 A and 34 A.
- the beam 133 A and the beam 131 form an acute angle ⁇ .
- the beam 134 A and the beam 132 form an acute angle equal to the acute angle ⁇ .
- the rotation stiffness of the gimbal 161 is less than that of the gimbal 125 shown in FIG. 123.
- the magnetic head slider 135 in the sixteenth embodiment can be more stably flied than that in the fourteenth embodiment shown in FIG. 23.
- FIG. 31 shows a magnetic head suspension unit 170 having a gimbal 171 according to a seventeenth embodiment of the present invention.
- a magnetic head slider 135 A of the mechanism 170 includes flanges 172 and 173 formed on the respective sides of the slider 35 A.
- a magnetic head slider fixing portion 130 A of the gimbal 171 includes an opening 174 having a size corresponding to the magnetic head slider 135 A.
- the opening 174 is of a rectangular shape defined by a rectangular frame 176 .
- the magnetic head slider 135 A engages the opening 174 , and the flanges 172 and 173 are made to adhere to the frame 176 by means of an insulation adhesive or an adhesive containing an insulator. In this manner, the magnetic head slider 135 A is fixed to the magnetic head slider fixing portion 130 A.
- the center G of gravity of the magnetic head slider 135 A is substantially located on the surface of the suspension 121 .
- the magnetic head slider 135 A is moved by exerting a force on the center G of gravity.
- an unnecessary rotation force about the center G of gravity of the magnetic head slider 135 A does not occur, and the unbalance of the magnetic head slider 135 A is reduced.
- the magnetic head slider 135 A can stably fly in the seek operation.
- the height of the magnetic head assembly can be reduced. Hence, it is possible to laminate layers of the head at reduced intervals and to provide an increased number of disks per unit length. As a result, it is possible to increase the volume storage density of the magnetic disk drive and hence the storage density.
- FIG. 33 shows a magnetic head suspension unit 180 having a magnetic head slider 135 B according to an eighteenth embodiment of the present invention.
- the magnetic head slider 135 B has a flange 181 formed around the circumference thereof.
- the magnetic head slider 135 B engages the opening 174 , and the flange 181 is adhered to the magnetic head slider fixing portion 130 A by means of an adhesive which can be an insulation adhesive or an adhesive containing an insulator.
- an adhesive which can be an insulation adhesive or an adhesive containing an insulator. That is, the eighteenth embodiment of the present invention differs from the seventeenth embodiment thereof in that the whole circumference of the magnetic head slider 135 B is made to adhere to the fixing portion 130 A.
- the adhesive strength is increased and the reliability of the magnetic head suspension unit is improved.
- FIG. 34 shows a magnetic head suspension unit 190 according to a nineteenth embodiment of the present invention.
- FIG. 35 shows a free end of a suspension of the magnetic head suspension unit 190 .
- the mechanism 190 is designed so that it does not have any influence of the stiffness of lead wires, which affect flying of the slider having a low airbearing stiffness.
- each of the lead wires has a diameter of 30 ⁇ m and has an additional length (free length) of 1 mm
- the rotation stiffness of the gimbal is approximately five times that of the gimbal in which there is no lead wire. This degrades the flying stability of the slider.
- the magnetic head suspension unit 190 has wiring patterns 191 , 192 , 193 and 194 , which are formed by patterning a copper thin film formed by, for example, plating by means of the photolithography technique.
- the wiring patterns 191 - 194 extend on a central portion of the lower surface of the suspension 121 in the longitudinal direction.
- Each of the wiring patterns 191 - 194 is approximately 5 ⁇ m thick and 50 ⁇ m wide. The thickness and width of the wiring patterns depend on the resistance of the conductive pattern and the capacity of the suspension 121 .
- Terminals 195 A- 195 D made of copper are formed on the base portion of the suspension 121 . Further, terminals 196 A- 196 D are formed in a terminal area 130 a of the magnetic head slider fixing portion 130 of the gimbal 125 . The tops of the terminals 195 A- 195 D and 196 A- 196 D are plated by, for example, Au. This plating contributes to preventing exposure of copper and improving the bonding performance. Ends of the wiring patterns 191 , 192 , 193 and 194 are respectively connected to the terminals 195 A, 195 B, 195 C and 195 D.
- the other ends of the two wiring patterns 191 and 192 extend along the beams 133 A and 131 , and are connected to the terminals 196 A and 196 B, respectively.
- the other ends of the wiring patterns 193 and 194 extend along the beams 134 A and 132 and are connected to the terminals 196 C and 196 D, respectively.
- the wiring patterns 191 , 192 , 193 and 194 are electrically insulated from the suspension 121 by means of an insulating film 197 , and are covered by a protection film 198 .
- the insulating film 197 and the protection film 198 are made of photosensitive polyimide and are grown to a thickness of approximately 5 ⁇ m.
- the insulating film 197 and the protection film 198 are respectively patterned by the photolithography technique.
- the thickness of the insulating film 197 is determined on the basis of a capacitance between the conductive pattern (made of Cu) and the suspension (made of stainless steel).
- polyimide has heat-resistance enough for an annealing process. Since polyimide has photosensitivity, it can be easily patterned. Further, the polyimide films 197 and 198 have corrosion resistance, and excellent reliability.
- terminals 195 A- 195 D and 196 A- 196 D are etched because these terminals are not covered by the protection film 198 .
- the surfaces of these terminals are covered by an Au film (not shown) having a thickness of approximately 1 ⁇ m formed by plating or vapor deposition.
- the magnetic head slider 135 is made to adhere to the fixing portion 130 by means of an adhesive which can be an insulation adhesive or an adhesive containing an insulator.
- the terminals 196 A- 196 D are located at a right angle with respect to terminals 1100 A- 1100 D of the magnetic head 148 formed on the end surface of the magnetic head slider 135 , and are respectively connected to the terminals 1100 A- 1100 D by means of Au balls 1101 A- 1101 D.
- the Au balls 1101 A- 1101 D are formed by means of, for example, a gold ball bonding device.
- the terminals 196 A- 196 D and terminals 1100 A- 1100 D are located as shown in FIG. 37.
- the terminals 1100 A- 1100 D are long in the direction of the height of the magnetic head slider 135 and are located so that these terminals 1100 A- 1100 D face the terminals 196 A- 196 D in the state where the head slider 135 is fixed to the fixing portion 130 .
- FIGS. 55 - 59 illustrate an embodiment with a bonding ball connection in more detail.
- FIG. 55 is a structural diagram of a magnetic disk apparatus to which another embodiment of the present invention directed to bonding balls is adapted
- FIG. 56 is a cross section of the structure in FIG. 55
- FIG. 57 is a front view of an actuator in FIG. 55
- FIG. 58 is an explanatory diagram of the seventeenth embodiment of this invention in FIG. 55
- FIG. 59 is a diagram for explaining how to connect the embodiment.
- FIG. 55 illustrates a magnetic disk apparatus which allows a head to float onto a magnetic disk to execute magnetic recording.
- a base 60 - 1 of the apparatus Provided on a base 60 - 1 of the apparatus are a 3.5-in magnetic disk 5 - 1 , which rotates around a spindle shaft 64 - 1 , and a magnetic circuit 63 - 1 .
- An actuator 4 - 1 is mounted rotatable around a rotary shaft 62 - 1 .
- a coil 41 - 1 is provided at the rear portion of this actuator 4 - 1 , as shown in FIGS. 59, 56 and 57 , and the coil 41 - 1 is located in the magnetic circuit 63 - 1 .
- each arm 3 - 1 are formed at the front portion of the actuator 4 - 1 , each arm 3 - 1 are formed at the front portion of the actuator 4 - 1 , each arm 3 - 1 provided with support plate (suspension) 7 - 1 which has a magnetic head core (core slider) 8 - 1 provided at the distal end.
- This actuator 4 - 1 together with the coil 41 - 1 and magnetic circuit 63 - 1 , form a linear actuator.
- the actuator 4 - 1 rotates around the rotary shalt 62 - 1 to move the magnetic head core 8 - 1 for a seek operation in a direction perpendicular to the tracks of the magnetic disk 5 - 1 (radial direction).
- “ 7 - 1 ” is a support plate (suspension) made of metal having a spring property, such as stainless. An insulating layer is coated on the support plate, and a pair of wiring patterns 71 - 1 and suspension connector terminals 72 - 1 are formed thereon by a copper pattern.
- the support plate 7 - 1 has its one end fixed to the arm 3 - 1 by laser spot welding or the like.
- “ 8 - 1 ” is a magnetic head core (core slider) which has a pair of core slider connector terminals 82 - 1 and a thin-film magnetic head 81 - 1 provided on the sides.
- the connector terminals 72 - 1 of the support plate 7 - 1 and the connector terminals 82 - 1 of the magnetic head core 8 - 1 are fixed with the positional relationship as shown in FIG. 58(B) and 59 (A), and gold balls W about 0.1 mm in diameter are made to contact both gold-plated connector terminals 82 - 1 and 72 - 1 and are subjected to pressure bonding an ultrasonic bonding by a ball bonder, the connector terminals 82 - 1 and 72 - 1 are electrically and mechanically connected via the gold balls W due to intermetal bonding.
- the magnetic disk 5 - 1 is located upward of the diagram.
- the support plate 7 - 1 is provided with the wiring patterns 71 - 1 and connector terminals 72 - 1 while the magnetic head core 8 - 1 is provided with eh connector terminals 82 - 1 , they can be connected by gold ball bonding. Therefor, even the minute magnetic head core 8 can easily be connected, thus accomplishing the miniaturization of the magnetic head assembly.
- FIG. 59( b ) shows a modification of the seventeenth embodiment in which a dummy terminal 83 - 1 is provided at the flow-in side of the magnetic head core 8 - 1 , and a dummy terminal 73 - 1 is provided on the wiring pattern 71 - 1 of the support plate 7 - 1 accordingly.
- gold balls W about 0.1 mm in diameter in contact with both gold-plated connector terminals 83 - 1 and 73 - 1 , pressure bonding and ultrasonic bonding are performed by a ball bonder, those connector terminals 83 - 1 and 73 - 1 are connected together via the gold balls W due to intermetal bonding.
- the magnetic head core 8 - 1 has both ends connected by the gold balls W to the support plate 7 - 1 , so that adhesion of the magnetic head core 8 - 1 to the support plate 7 - 1 is unnecessary and the connection can be made by the ball bonding step alone, further facilitating the assembly.
- the wiring patterns 191 - 194 bypass holes 1102 A, 1102 B and 1102 C, as shown in FIG. 34 and extend up to an area close to the head slider 135 .
- the hole 1102 c is used to fix the suspension 121 to the arm 122 (not shown in FIG. 34).
- the holes 1102 A, 110 B and 1102 C are sized such that a tool can be inserted therein.
- dummy patterns 1103 A- 1103 D and 1104 A- 1104 D are provided so that these dummy patterns are symmetrical to the bypassing portions of the wiring patterns 191 - 194 with respect to the holes 1102 A and 1102 B.
- the insulating film 197 and the protection film 198 are provided for the dummy patterns 1103 A- 1103 D and 1104 A- 1104 D in the same manner as the wiring patterns 191 - 194 .
- the dummy patterns 1103 A- 1103 D and 1104 A- 1104 D are provided in order to balance the mechanical stiffness of the suspension 121 in the direction of the width of the suspension 121 .
- the wiring patterns 191 - 194 are arranged so that these patterns form a loop.
- This loop functions as an antenna, which receives noise components contained in the head signals.
- the degree of the noise components is increased.
- the wiring patterns 191 and 192 respectively connected to the terminals 196 A and 196 B are arranged between the hole 1102 A and the magnetic head slider 135 , and all the wiring patterns 191 - 194 are gathered in the vicinity of the hole 1102 A.
- the dummy patterns 1104 A- 1104 D are formed. For the same reason as above, the dummy patterns 1103 A- 1103 D are formed in the vicinity of the hole 1102 B.
- auxiliary films 1106 and 1107 having a belt shape are formed along the right and left ends of the suspension 121 .
- the auxiliary films 1106 and 1107 are provided in order to receive a clamping force generated when the suspension 121 is clamped in a bending process which will be described later. Such a clamping force is also received by the wiring patterns 191 - 194 .
- the clamping force is distributed so that the clamping force is exerted on not only the wiring patterns 191 - 194 but also the auxiliary films 1106 and 1107 . Hence, it is possible to prevent the wiring patterns 191 - 194 from being damaged.
- a convex dummy pattern 1108 is provided in order to prevent an adhesive from flowing from the fixing portion 130 when the slider 135 is fixed to the fixing portion 130 and to prevent the slider 135 from being tilted due to the thickness of the wiring patterns. More particularly, the convex pattern 1108 is used to form a groove in which an insulation adhesive used to fix the slider 135 is saved between the pattern 1108 and the terminals 196 A- 196 D. Further, the convex pattern 1108 is designed to have the same height as the patterns having the terminals 196 A- 196 D.
- the slider 135 will be inclined with respect to the fixing portion 130 due to the height of the terminals 194 A- 194 D. This degrades the flying stability of the heads. Further, the use of the convex dummy pattern 1108 increases the height of the adhesive to thus improve the insulation performance.
- the convex pattern 1108 can be formed by a cooper-plated thin film similar to the wiring patterns 191 - 194 .
- the protection film 198 covers the convex pattern 1108 .
- the adhesive is provided on a step part between the wiring patterns and the convex pattern 1108 .
- the suspension 121 is produced by a process shown in FIG. 38.
- a pattern formation step 1110 is performed. More particularly, photosensitive polyimide is coated on a stainless plate.
- the insulating film 197 is formed by the photolithography technique.
- a copper film is formed by the plating process, the vapor deposition process or the like, and is patterned into the wiring patterns 191 - 194 by the photolithography technique.
- photosensitive polyimide is coated and is patterned into the protection film 198 and the auxiliary films 1106 and 1107 by the photolithography technique.
- Polyimide can be coated by a spin-coat process, and is patterned and etched.
- a thin film, such as a Cr film can be formed in order to improve the adhesiveness between the insulating film and the Cu film and between the Cu film and the protection film and to improve the reliability of the adhesion.
- an etching step 111 is performed in order to form the openings 126 - 129 and the holes 1102 A- 1102 C and the outward form of the suspension in the stainless plate.
- FIG. 39 shows suspensions 1202 before punching for cutting off bridge portions (not shown) to provide pieces, so that the suspensions 1202 are formed in a stainless plate 1201 and arranged in rows and columns.
- a bending step 1112 is performed by bending the respective ends of each of the suspensions 1202 formed in the stainless plate 1201 , so that ribs 121 a are formed.
- the bending step 1112 can be performed by press so that the suspensions 1202 are processed at the same time.
- an annealing step 1113 is performed at a temperature of approximately 400° C., so that internal stress can be removed. Further, a slider adhering step and an Au bonding step can be automatically carried out before the suspensions 1202 are punched. Hence, it is possible to automatically perform the production process shown in FIG. 38 and reduce the number of steps and the cost thereof.
- the suspension 121 can be produced without performing the annealing step 1113 .
- the pattern formation step 1110 and the etching step 1111 are performed, and subsequently the slider adhering step and the Au bonding step are carried out. Thereafter, the bending step 1112 is carried out to form the ribs 121 a.
- the magnetic head slider 135 has the aforementioned two terminals 1100 A and 1100 B.
- the two wiring patterns 191 A and 192 A are provided so that these wiring patterns extend on only the beams 132 and 134 A, while two dummy patterns 1210 and 1211 are provided so as to extend on the beam 131 and 133 A in order to balance the mechanical stiffness of the suspension 121 in the direction of the width of the suspension 121 .
- the magnetic head suspension unit 190 has the following features.
- the crimp connection using the Au balls 1101 A- 1101 D enables automatic assembly and non-wire bonding between head terminals and pattern terminals.
- the beams may be curved.
- FIG. 42 shows a back surface of a magnetic head suspension unit 1230 according to the twelfth embodiment of the present invention.
- FIG. 43 shows a 1.8-inch-type magnetic disk drive 1231 to which the magnetic head suspension unit 1230 is applied.
- the magnetic disk drive 1231 has an enclosure 1232 having almost the same dimensions as those of an IC memory card. In the enclosure 1232 , provided are a magnetic disk 1233 having a diameter of 1.8 inches, and an actuator to which two sets of magnetic head suspension units are attached. The magnetic disk drive 1231 is more compact than the magnetic disk drive 1220 shown in FIG. 3.
- a magnetic head slider 135 C is made compact in accordance with light-sizing of the magnetic disk drive 1231 . More particularly, dimensions a ⁇ b of the magnetic head slider 135 C are 0.8 mm ⁇ 1.0 mm, and are approximately one-quarter the area of the magnetic head slider 135 shown in FIG. 23. In order to stably fly the compact magnetic head slider 135 C, it is necessary to considerably reduce the stiffness without decreasing the resonance frequency, as compared with the magnetic head suspension unit 130 .
- a suspension 1235 shown in FIG. 42 is made of stainless, and has a base portion fixed to an arm 1236 of the actuator 1234 (see FIG. 43).
- the suspension 1235 has a width W 2 of approximately 2 mm, a length L of approximately 9 mm, and a thickness to of approximately 25 ⁇ m, and is approximately a half of the volume of the suspension 121 shown in FIG. 23.
- the suspension 1235 is diminished, and hence the resonance frequency of bending which will be described later is high.
- the suspension 1235 is a sheet-shaped piece, and a flat plate piece to which a bending process has not been subjected. Hence, there is no problem of a bending process error which degrades the flying stability of the magnetic head slider.
- the suspension 1235 includes a suspension main body 1237 and a gimbal 1238 located on the end side of the suspension 1235 .
- the gimbal 1238 has a substantially U-shaped opening (through hole) 1239 formed in the suspension 1235 .
- the gimbal 1238 includes a magnetic head slider fixing portion 1240 , a first beam 1241 , a second beam 1242 , a third beam 1244 , and a connecting portion 1243 .
- the magnetic head slider fixing portion 1240 has a size corresponding to the magnetic head slider 135 C.
- the first beam 1241 and the second beam 1242 extend along respective longitudinal ends of the suspension 1235 from the end thereof.
- the connecting portion 1243 extends in the direction of the width of the suspension 1235 , and connects the first beam 1241 and the second beam 1242 together.
- the third beam 1244 extends from the connecting portion 1243 to the magnetic head slider fixing portion 1240 in the longitudinal direction of the suspension 1235 .
- the magnetic head slider fixing portion 1240 is connected to the main body 1237 of the suspension 1235 via the third beam 1244 , the connecting portion 1243 and the first and second beams 1241 and 1242 .
- the rotation stiffness of the suspension 1230 can be reduced to a small value due to bending of the entire beams.
- holes 1245 , 1246 and 1247 with which a tool is engaged, and a pair of slits 1248 and 1249 are formed in the main body 1237 of the suspension 1235 . Adjustment slits 1248 and 1249 are used to reduce the rotation stiffness of the suspension.
- the holes 1245 , 1246 and 1247 and the slits 1248 and 1249 are formed by etching.
- the connectors 195 A- 195 D, 196 A- 196 D and the wiring patterns 191 - 194 are formed symmetrically with respect to the longitudinal direction of the suspension 1235 .
- the magnetic head slider 135 C is made to adhere to the fixing portion 1240 , and the terminals 196 A- 196 D and 1100 A- 1100 D are respectively connected to each other by means of Au balls, as in the case shown in FIG. 37.
- the structure shown in FIG. 42 does not use dummy patterns because the length and the width of the suspension 1235 are less than those of the suspension shown in FIG. 34 and the loop formed by the wiring patterns is smaller than that shown in FIG. 34. However, it is preferable to arrange the wiring patterns and provide the dummy patterns as shown in FIGS. 34 and 35 in order to reduce the noise from the heads.
- the free end of the arm 1236 is bent so that a substantially V-shaped cross section of the arm 1236 is formed in which the “V” is inverted.
- the free end of the arm 1236 has an upward slant portion 1236 a and a downward slant portion 1236 b declined at an angle ⁇ with respect to the horizontal direction.
- the magnetic disk drive 1231 uses two magnetic head suspension units 1230 so that the single magnetic disk 1233 is sandwiched between the mechanisms 1230 .
- the suspension 1235 causes the magnetic head slider 135 C to come into contact with the magnetic disk 1233 when the magnetic disk 1233 is not being rotated.
- the main body 1237 of the suspension 1235 is caused to be bent and elastically deformed.
- the elastic force stored in the main body 1237 of the suspension 1235 generates a load F 1 , which urges the magnetic head slider 35 C towards the magnetic disk 1233 .
- a wide gap 1250 can be formed between an end 1236 c of the arm 1236 and the magnetic disk 1233 , as compared with a case indicated by a two-dot chained line in which the arm 1236 is simply bent downwards.
- the main body 1237 of the suspension 1235 and the third beam 1244 are bent.
- a moment is exerted by a center 1251 of the magnetic head slider 35 C.
- a moment M 1 directed counterclockwise is exerted by the suspension main body 1237 and the first and second beams 1241 and 1242 .
- a moment M 2 directed clockwise is exerted on the third beam 1244 .
- the dimensions of the suspension 1235 are selected so that the moments M 1 and M 2 are balanced.
- the suspension 1235 is 9 mm long, and the gimbal 1238 is 2.5 mm long.
- the length and width of the main body 1235 of the suspension 1237 are 5.7 mm and 2 mm, respectively.
- the magnetic head slider 135 C is rotated in the pitching direction indicated by arrow 144 in such a manner that the first, second and third beams 1241 , 1242 and 1244 and the suspension main body 1237 are bent. At this time, all the beams 1241 , 1242 and 1244 are bent so as to be deformed in the form of arch shapes.
- the gimbal 1238 is bent and hence the suspension main body 1237 is bent. Hence, the pitch stiffness can be greatly reduced.
- the magnetic head slider 135 C is rotated in the rolling direction indicated by arrow 145 in such a manner that the first and second beams 1241 and 1242 are respectively bent in the opposite directions and the suspension main body 1237 is twisted. At this time, the gimbal 1238 is bent and hence the suspension main body 1237 is bent. Hence, the rolling stiffness can be greatly reduced.
- the suspension 1235 is bent and deformed, as shown in FIG. 47. More specifically, the suspension main body 1237 , and the first, second and third beams 1241 , 1242 and 1244 of the gimbal 1238 are bent as shown in FIG. 45.
- the overall suspension 1235 is formed flexibly, but the resonance frequency of the first-order bend is high, while the stiffness is small.
- the suspension 1235 is twisted as shown in FIG. 48.
- the gimbal 1238 is deformed and hence the suspension m body 1237 is deformed.
- the overall suspension 1235 is flexibly formed, but the resonance frequency of the first-order twist is high while the stiffness thereof is low.
- Tables 3 and 4 show characteristics of the magnetic head support mechanism 1230 according to the twelfth embodiment of the present invention and the magnetic head suspension unit 130 of the fourteenth embodiment thereof shown in FIG. 23.
- TABLE 3 COMPARISON OF STIFFNESS (static characteristics by computer simulation) Stiffness 7th embodiment 1st embodiment pitch stiffness 0.44 grf cm/rad 1.5 grf cm/rad roll stiffness 0.24 grf cm/rad 1.5 grf cm/rad up/down stiffness 0.36 grf/mm 0.55 grf/mm equivalent weight ratio 0.76 0.74
- Table 3 the pitch stiffness, the roll stiffness, and the up/down stiffness of the suspension 1235 obtained by means of a computer simulation. It can be from Table 3 that the pitch stiffness and the roll stiffness of the twelfth embodiment of the present invention are approximately one-quarter of those of the fourteenth embodiment thereof.
- Table 4 shows the resonance frequencies of the fourteenth and twelfth embodiments of the present invention obtained by a computer simulation. It can be seen from Table 4 that the first-order bend resonance frequency, the first-order twist resonance frequency and the lateral resonance frequency are kept very high.
- the magnetic head suspension unit 1230 according to the twelfth embodiment of the present invention has a resonance frequency as high as that of the magnetic head suspension unit 130 according to the fourteenth embodiment, and stiffness much less than that of the mechanism 130 .
- the compact magnetic head slider 135 C can be stably flied.
- the base portion of the suspension 1237 is bent, so that the suspension is supported in the same manner as shown in FIG. 23 and the load F 1 shown in FIG. 45 is obtained.
- the base portion of the suspension 1237 is bent, so that the suspension is supported in the same manner as shown in FIG. 23 and the load F 1 shown in FIG. 45 is obtained.
- only portions 1255 and 1256 outside of the slits 1248 and 1249 are bent. Hence, unnecessary strain is not exerted on the wiring patterns 191 - 194 located between the slits 1248 and 1249 .
- a first variation of the gimbal 1238 of the suspension 1235 will be described.
- a gimbal 1238 ⁇ 1 shown in FIG. 49 has a first beam 1244 ⁇ 1 having a long width A, and an opening 1239 ⁇ 1 having a long length B.
- First and second beams 1241 ⁇ 1 and 1242 ⁇ 1 are long.
- FIG. 50 shows a second variation 1238 ⁇ 2 of the gimbal 1238 .
- the gimbal 1238 ⁇ 2 has first and second beams 1241 ⁇ 2 and 1242 ⁇ 2 each having a small width C.
- FIG. 51 shows a third variation 1238 ⁇ 3 of the gimbal 1238 .
- the gimbal 1238 ⁇ 3 has first and second variations 1241 ⁇ 3 and 1242 ⁇ 3 having a large width D.
- FIG. 52 shows a fourth variation 1238 ⁇ 4 of the gimbal 1238 .
- the gimbal 1238 ⁇ 4 has a fourth beam 1260 connecting the center of the end of the magnetic head slider fixing portion 1240 and the suspension main body 1237 together.
- the fourth beam 1260 functions to prevent a deformation of the magnetic head slider fixing portion 1240 , but increases the rotation stiffness. Hence, it is desired that the width of the fourth beam 1260 be as small as possible and the length thereof are as long as possible.
- FIG. 53 shows a fifth variation 1238 ⁇ 5 of the gimbal 1238 .
- the gimbal 1238 ⁇ 5 has first and second arch-shaped beams 1241 ⁇ 5 and 1242 ⁇ 5 .
- a bent connecting plate 1261 is fixed to an arm 1236 A, and the suspension 1235 is fixed to the connecting plate 1261 . Hence, it is not necessary to subject the arm 1236 A to bending stresses.
- the third beam 1244 shown in FIG. 42 has the same width as the fixing portion 1240 and is integrated with the fixing portion 1240 .
- the load applied to the magnetic head slider is generated by bending the spring portion of the suspension.
- the arm fixing structure used in the twelfth embodiment of the present invention in which the spring portion is kept flat.
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Abstract
Description
- 1. Field of the Invention
- The present invention relates to a magnetic head assembly having a thin-film or MR type magnetic head used for a magnetic disk drive.
- 2. Description of the Related Art
- Recently, in conventional magnetic disk drives, monolithic type magnetic heads have been replaced with thin-film or MR type magnetic heads.
- FIG. 1A is an exploded view of an example of a magnetic head assembly (which can also be referred to as a magnetic head suspension unit) having a thin-film type magnetic head used for the conventional magnetic disk drives. FIG. 1B is an exploded view of a part of the magnetic head suspension unit shown in FIG. 1A. In the present specification, the magnetic head suspension unit refers to an assembly of a spring arm having a magnetic head mounted on an end of the spring arm. The other end of the spring arm is adapted to be mounted on a member of a magnetic head positioning mechanism.
- Referring now to FIG. 1A, one end (a base portion1 a) of a spring arm (suspension) 1 formed of an elastic plate is mounted to a member of a magnetic head positioning mechanism (not shown in the figure) via a plate-like spacer 2. A
gimbal 3 is mounted on another end 1 b of thespring arm 1. Thegimbal 3 is mounted, as shown in FIG. 1B, on thespring arm 1 by means of laser welding at positions indicated by x. A core slider (head slider) 4 of a magnetic head h is mounted by adhesive on thegimbal 3. - Two
magnetic head elements 5 are formed on a rear side surface of the magnetic head, themagnetic head elements 5 being connected by lead wires 6 which lead to aread wire 8 covered with an insulatingtube 7 fixed to thespring arm 1. Thelead wire 8 is lead to a recording/reproducing circuit 9 shown in FIG. 2. - The
spring arm 1 is slightly bent near the base portion 1 a so that a bent portion 1 c is formed so as to generate a spring force. - FIG. 2 is an exploded view of a conventional magnetic disk drive in which two magnetic head suspension units shown in FIG. 1A are used.
- Two magnetic head suspension units are mounted on a driving
arm 13 which pivots about anaxis 12 so that amagnetic disk 10 accommodated inside the magnetic head drive is sandwiched between two of thecore sliders 4 mounted on therespective spring arms 1. Each of thecore sliders 4 is pressed to a respective surface of themagnetic disk 10 by the spring force generated by the bent portion 1 c. - When the
magnetic disk 10 is rotated at a high speed, the magnetic heads h float, if the magnetic heads h are of the floating type, on the respective surface of themagnetic disk 10 due to an air flow generated by the rotation of themagnetic disk 10. If the magnetic heads h are contact type magnetic heads, the magnetic heads h do not float, but instead slide on the respective surfaces of themagnetic disk 10. The magnetic heads h are moved to respective target tracks on the surfaces of themagnetic disk 10 by pivoting the spring arms about theaxis 12. - FIG. 3 is a perspective view of a thin-film type magnetic head. FIG. 4 is an enlarged cross sectional view of the thin-film type magnetic head shown in FIG. 3 taken along a line A-A of FIG. 3.
- The thin-film type magnetic head shown in FIG. 3 comprises the
slider 4 andhead elements 5. Thehead elements 5 are formed by means of a film deposition technique and lithography.Terminals 15 a and 15 b for recording/reproducing coils are provided near thehead elements 5. - Each of the
head elements 5 comprises a lowermagnetic pole 16, an uppermagnetic pole 17 and a thin-film coil 19 wound around a connectingportion 18 between the lowermagnetic pole 16 and the uppermagnetic pole 17. Agap insulating layer 20 is provided between the lowermagnetic pole 16 and the uppermagnetic pole 17 so that a gap G having a predetermined width is formed between the two poles. The gap G faces the surface of themagnetic disk 10 to perform an magnetic recording/reproducing operation. - In the construction of the magnetic head suspension unit shown in FIG. 1 in which the
lead wire 8 is covered with the insulatingtube 7, the insulatingtube 7 occupies a relatively large space to prevent miniaturization of the magnetic disk drive. Additionally, the insulatingtube 7 makes an assembling operation difficult, particularly an automated assembling operation. Further, there is a strong possibility that thelead wire 8 will pick up noises, resulting in degradation of an S/N ratio of a signal sent via thelead wire 8. - In order to eliminate the above-mentioned problems, a method for forming a signal transmitting line on a spring arm is suggested in Japanese Laid-Open Patent Application No.4-21918. In the method, a signal line is formed of a pattern of a conductive layer on an insulating layer formed on the spring arm. However, the method has a problem in that the signal transmitting line formed of the conductive layer is easily damaged or broken during a process for forming the bent portion1 c shown in FIG. 1A.
- Japanese Laid-Open Patent Application No.4-111217 discloses a magnetic head suspension unit in which a flexible printed circuit board is attached to a spring arm, and a portion of the flexible circuit board corresponding to the above of the spring arm bent portion is not adhered to the spring arm. Instead, in this construction, the portion of the flexible printed circuit board corresponding to the bent portion of the spring arm is free, and thus the there is no bending stress applied to the flexible printed circuit board. However, this construction cannot be applied to a highly miniaturized spring arm such as a spring arm having a thickness of a few microns and a 4.6 mm width.
- There is another problem in that ability of the insulating
layers film coil 19 and thepoles layers - If the insulation between the thin-
film coil 19 and thepoles magnetic poles core slider 4 being damaged. Additionally, when the magnetic disk drive is in operation, an electric discharge may occur between themagnetic disk 10 and themagnetic poles core slider 4 is damaged, the floating characteristic of the magnetic head is deteriorated, which condition causes a generation of noises in the recording/reproducing signal. If the magnetic head is a contact type head, the damaged surface of the magnetic head may scratch themagnetic disk 10. - Problems similar to the above-mentioned problems may occur when the core slider is miniaturized. That is, when the magnetic head is heated, the magnetic head tends to expand due to the thermal expansion, but a portion of the core slider attached to the gimbal or the spring arm by adhesive cannot expand in accordance with the expansion of the magnetic head. This creates bending of the core slider, and thus the floating characteristic of the magnetic head may be deteriorated.
- It is a general object of the present invention to provide an improved and useful magnetic head assembly and a magnetic disk drive having such a magnetic head suspension unit in which the above-mentioned disadvantages are eliminated.
- A more specific object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which damaging of a conductive-pattern layer formed on a spring arm during a process of bending the spring arm can be prevented.
- Another object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which no insulation breakage occurs due to generation of static electricity.
- Another object of the present invention is to provide a magnetic head assembly and a magnetic disk drive in which thermal deformation of a slider core is prevented.
- In order to achieve the above-mentioned objects, there is provided according to the present invention, a magnetic head assembly comprising:
- a slider on which a magnetic head is mounted, the slider having terminals of the magnetic head;
- a gimbal portion on which the slider is mounted;
- terminals of wiring lines; and
- balls bonding the terminals of the wiring lines and the terminals of the slider.
- The magnetic head assembly may be configured so that the balls are made of gold.
- The magnetic head assembly may be configured so that the terminals of the wiring lines are provided on the gimbal portion.
- The magnetic head assembly may be configured so that the wiring lines are formed by a wiring pattern.
- The magnetic head assembly may be configured so that the slider is provided on a surface of the gimbal portion on which the wiring lines are provided.
- The magnetic head assembly may be configured so that the slider is provided on the gimbal portion so that the terminals of the wiring pattern and the terminals of the slider face each other in an orthogonal formation.
- The magnetic head assembly may be configured so that the gimbal portion is a part of a suspension so that the gimbal portion is integrally formed with the suspension.
- The magnetic head assembly may be configured so that the wiring lines are formed by a wiring pattern formed on the suspension.
- The magnetic head assembly may be configured so that the slider is provided on a surface of the gimbal portion on which the wiring lines are provided.
- The magnetic head assembly may be configured so that the slider is provided on the gimbal portion so that the terminals of the wiring pattern and the terminals of the slider face each other in an orthogonal formation.
- The above objects of the present invention are also achieved by a magnetic disk drive comprising:
- an enclosure;
- a magnetic disk provided in the enclosure;
- a magnetic head assembly provided in the enclosure; and
- an actuator to which the magnetic head suspension unit is fixed, the actuator moving the magnetic head assembly above the magnetic disk, wherein the magnetic head assembly is configured as described above.
- The other objects, features and advantages of the present invention will be apparent from the following detailed description when read in conjunction with the accompanying drawings, in which:
- FIG. 1A is an exploded view of an example of a magnetic head assembly having the thin-film type magnetic head used for the conventional magnetic disk drives;
- FIG. 1B is an exploded view of a part of the magnetic head assembly shown in FIG. 1A;
- FIG. 2 is an exploded view of a conventional magnetic disk drive in which two magnetic head assemblies shown in FIG. 1A are used;
- FIG. 3 is a perspective view of a thin-film type magnetic head;
- FIG. 4 is an enlarged cross sectional view of the thin-film type magnetic head shown in FIG. 3 taken along a line A-A of FIG. 3;
- FIG. 5A is a perspective view of a first embodiment of a magnetic head assembly according to the present invention;
- FIG. 5B is an enlarged cross sectional view taken along a line b-b of FIG. 5A;
- FIG. 6A is a perspective view of the spring arm shown in FIG. 5A in a state where a magnetic head has not been mounted on a gimbal;
- FIG. 6B is an illustration showing a process for forming conductive-pattern layers on the spring arm;
- FIGS. 7A through 7C are illustrations showing a process for bending the bent portions shown in FIG. 6A;
- FIG. 8A is a perspective view of a second embodiment of a magnetic head assembly according to the present invention;
- FIG. 8B is an enlarged partial cross sectional view taken along a line b-b of FIG. 8A;
- FIG. 8C is an enlarged partial cross sectional view taken along a line c-c of FIG. 8A;
- FIG. 8D is a partial cross sectional view of a variation of the spring arm shown in FIG. 8A;
- FIG. 9A is a perspective view of a third embodiment of a magnetic head assembly according to the present invention;
- FIG. 9B is a cross sectional view taken along a line b-b of FIG. 9A;
- FIG. 10 is a perspective view of a fourth embodiment of a magnetic head assembly according to the present invention;
- FIG. 11A is a perspective view of a fifth embodiment of a magnetic head assembly according to the present invention;
- FIG. 11B is an enlarged partial cross sectional view taken along a line b-b of FIG. 11A.
- FIG. 12A is a perspective view of a sixth embodiment of a magnetic head assembly according to the preset invention;
- FIG. 12B is an enlarged partial cross sectional view taken along a line b-b of FIG. 12A;
- FIG. 12C is an enlarged partial cross sectional view taken along a line c-c of FIG. 12C;
- FIG. 13A is a perspective view of a seventh embodiment of a magnetic head assembly according to the present invention;
- FIG. 13B is a variation of the embodiment shown in FIG. 13A;
- FIG. 14 is a perspective view of an eighth embodiment of a magnetic head assembly according to the present invention;
- FIG. 15A is a perspective view of the magnetic head shown in FIG. 14;
- FIG. 15B is a cross sectional view taken along a line b-b of FIG. 15A;
- FIG. 16 is an exploded view of an essential part of a ninth embodiment of a magnetic head assembly according to the present invention;
- FIG. 17 is an exploded view of an essential part of a variation of the ninth embodiment shown in FIG. 16;
- FIG. 18 is a perspective view of an essential part of a tenth embodiment of a magnetic head assembly according to the present invention;
- FIG. 19 is an exploded view of an eleventh embodiment of a magnetic head assembly according to the present invention;
- FIG. 20A is a perspective view of a spring arm of a twelfth embodiment of a magnetic head assembly according to the present invention;
- FIG. 20B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 20A;
- FIGS. 21A through 21F are illustrations of variations of the hole shown in FIG. 20A; and
- FIG. 22A is a perspective view of a spring arm of a thirteenth embodiment of a magnetic head assembly according to the present invention;
- FIG. 22B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 22A;
- FIG. 22C is an enlarged cross sectional view showing a variation of the mounting structure shown in FIG. 22B;
- FIG. 23 is a perspective view of a magnetic head assembly according to a fourteenth embodiment of the present invention;
- FIG. 24 is a plan view of a 3.5-inch magnetic disk drive to which the magnetic head assembly shown in FIG. 23 is applied;
- FIG. 25 is a perspective view of a first-order bend state of a suspension shown in FIG. 23;
- FIG. 26 is a perspective view of a first-order twist state of the suspension shown in FIG. 23;
- FIG. 27 is a perspective view of the upper side of the magnetic head assembly shown in FIG. 23;
- FIG. 28 is a side view of the magnetic head assembly shown in FIG. 23;
- FIG. 29 is a perspective view of a magnetic head assembly according to a fifteenth embodiment of the present invention;
- FIG. 30 is a perspective view of a magnetic head assembly according to a sixteenth embodiment of the present invention;
- FIG. 31 is a perspective view of a magnetic head assembly according to the twelfth embodiment of the present invention;
- FIG. 32 is a side view of the mechanism shown in FIG. 31;
- FIG. 33 is a perspective view of a magnetic head assembly according to an eighteenth embodiment of the present invention;
- FIG. 34 is a perspective view of a magnetic head assembly according to a nineteenth embodiment of the present invention;
- FIG. 35 is a plan view of a free-end part of a suspension shown in FIG. 34;
- FIG. 36 is a sectional-view taken along a line XIV-XIV shown in FIG. 34;
- FIG. 37 is a perspective view of a magnetic head slider shown in FIG. 34;
- FIG. 38 is a flowchart of a production process for the suspension shown in FIG. 34;
- FIG. 39 is a plan view of a plate obtained after an etching step shown in FIG. 38 is carried out;
- FIG. 40 is a flowchart of another production process for the suspension shown in FIG. 34;
- FIG. 41 is a perspective view of a variation of the nineteenth embodiment of the present invention;
- FIG. 42 is a perspective view of a magnetic head assembly according to a twelfth embodiment of the present invention;
- FIG. 43 is a plan view of a magnetic disk drive to which the magnetic head assembly shown in FIG. 42 is applied;
- FIGS. 44A and 44B are respectively plan and side views of the magnetic head assembly shown in FIG. 42;
- FIG. 45 is a side view of a state observed when the magnetic head assembly shown in FIG. 42 is provided in the magnetic disk drive;
- FIG. 46 is an emphasized view of the state in FIG. 45;
- FIG. 47 is a side view of a first-order bend state of a suspension used in the twelfth embodiment of the present invention;
- FIG. 48 is a side view of a first-order twist state of the suspension used in the twelfth embodiment of the present invention;
- FIG. 49 is a plan view of a first variation of a gimbal of the suspension used in the twelfth embodiment of the present invention;
- FIG. 50 is a plan view of a second variation of the gimbal of the suspension used in the twelfth embodiment of the present invention;
- FIG. 51 is a plan view of a third variation of the gimbal of the suspension used in the twelfth embodiment of the present invention;
- FIG. 52 is a plan view of a fourth variation of the gimbal of the suspension used in the twelfth embodiment of the present invention;
- FIG. 53 is a plan view of a fifth variation of the gimbal of the suspension used in the twelfth embodiment of the present invention; and
- FIG. 54 is a side view of a variation of the twelfth embodiment of the present invention.
- FIG. 55 is a top view of another embodiment of a magnetic disk apparatus of the present invention;
- FIG. 56 is a cross section of the magnetic disk apparatus in FIG. 55;
- FIG. 57 is a top view of an actuator in FIG. 55;
- FIG. 58 is a perspective view of a magnetic head assembly according to a further embodiment of the present invention;
- FIG. 59 illustrates another connecting mechanism of the magnetic head assembly in FIG. 58;
- A description will now be given, with reference to FIGS. 5A and 5B, of a first embodiment of the present invention. FIG. 5A is a perspective view of a first embodiment of a magnetic head assembly according to the present invention, and FIG. 5B is an enlarged cross sectional view taken along a line b-b of FIG. 5A. Hereinafter, the magnetic head assembly is also referred to a magnetic head suspension unit or merely suspension unit. In FIGS. 5A and 5B, parts that are the same as the parts shown in FIG. 1A are given the same reference numerals, and descriptions thereof will be omitted.
- The first embodiment according to the present invention comprises the
spring arm 1 and theslider core 4 of the magnetic head. Agimbal 24 supported bybridge portions spring arm 1. The core slider (head slider) 4 of the magnetic head is mounted on thegimbal 24 by an adhesive which has an insulation effect and can be an insulation adhesive or an adhesive containing an insulator. The insulation adhesive is an insulator in which the insulator itself has the insulation effect. - The base portion (attachment portion)1 a of the
spring arm 1 is fixed to a member of a magnetic head positioning mechanism. Conductive-pattern layers 25 run from the base portion la to thegimbal 24 so as to transmit signals to/from the magnetic head. - FIG. 6A is a perspective view of the
spring arm 1 shown in FIG. 5A in a state where the magnetic head has not been mounted on thegimbal 24. In FIG. 6A, a portion of thecore slider 4 is also shown to explain electrical connection between the magnetic head and the conductive-pattern layers 25. Apad 25 a is formed at the end of each of the two conductive-pattern layers 25. The core slider of the magnetic head is also provided withpads 26. When thecore slider 4 is mounted on thegimbal 24, thepads 26 make contact with therespective pads 25 a. Thepads 26 and thepads 25 a are then soldered together to assure an electric connection. It should be noted that thecore slider 4 in FIG. 6A is viewed from a direction indicated by an arrow B of FIG. 5A. - The conductive-pattern layers25 on the
spring arm 1 are formed by a process shown in FIG. 6B. As shown by FIG. 6B-2, an insulatinglayer 27 is formed on thespring arm 1 by applying a polyimide resin over thespring arm 1 made of stainless steel. The thickness of thespring arm 1 is about 25 μm, and the thickness of the insulatinglayer 27 is 3-4μm. Abase layer 28 is then formed on the insulatinglayer 27, as shown in FIG. 6B-3, by sputtering copper (Cu) onto the insulatinglayer 27. Thebase layer 28 may instead be formed by vapor deposition or chemical plating. - Using the
base layer 28, electro plating is performed to form acopper layer 29 on thebase layer 28, as shown in FIG. 6B-4. As shown in FIG. 6B-5, thebase layer 28 and thecopper layer 29 are etched so that the conductive-pattern layers 25 remain on thespring arm 1. Lastly, polyimide resin is applied over the conductive-pattern layers 25 so as to form an insulatingfilm 30 which covers the conductive-pattern layers 25 to protect them. - If a bending process is performed by applying a pressing force to the conductive-pattern layers25 formed on the
spring arm 1, the conductive-pattern layers 25 may be damaged or destroyed. In order to eliminate this problem, in the first embodiment of the present invention,rectangular holes 31 a and 31 b are formed on thespring arm 1, as shown in FIG. 5A, on either side of the conductive-pattern layers 25. Therectangular holes 31 a and 31 b separate a portion of thespring arm 1, on which the conductive-pattern layers 25 are formed, frombent portions spring arm 1. Therectangular holes 31 a and 31 b may instead be slits 32 a and 32 b as shown in FIG. 6A. - FIGS. 7A through 7C are illustrations showing a process for bending the
bent portions roller 34 havinglarger diameter portions larger diameter portions bent portions bent portions spring arm 1 are placed on a rubber table 36. Theroller 34 is then rolled, as shown in FIG. 7B, on thebent portion bent portions spring arm 1, on which portion the conductive-pattern layers are formed, between thebent portions - According to the present embodiment, the
roller 34 is not pressed on the portion where the conductive-pattern layers 25 have been formed, and thus no damage to the conductive-pattern layers 25 occurs. - A description will now be given, with reference to FIGS. 8A through 8D, of a second embodiment according to the present invention. FIG. 8A is a perspective view of a second embodiment of a magnetic head suspension unit according to the present invention; FIG. 8B is an enlarged partial cross sectional view taken along a line b-b of FIG. 8A; FIG. 8C is an enlarged partial cross sectional view taken along a line c-c of FIG. 8A. FIG. 8D is a partial cross sectional view of a variation of the spring arm shown in FIG. 8A.
- In the present embodiment, a recessed
portion 39 is formed in the elastic portion R where an elastic force is generated. The conductive-pattern layers 25 are formed in the recessedportion 39. The recessedportion 39 covers an entire length C of the elastic portion R and a width B so as to cover the portions of the conductive-pattern layers 25 located in the elastic portion R of thespring arm 1. - In this embodiment, a portion of the insulating
layer 27 shown in FIG. 6B-2 is formed also inside the recessedportion 39. Thebase layer 28 and thecopper layer 29 are then formed on the entire surface of the insulatinglayer 27 including the portion thereof inside the recessedportion 39 so as to form the conductive-pattern layers 25. Lastly, the insulatinglayer 30 is formed on the conductive-pattern layers 25 so that a top surface of the insulatinglayer 30 located inside the recessedportion 39 is below the surface of thespring arm 1 as shown in FIG. 8B. - In the present invention, since the portion inside the recessed
portion 39 do not come into contact with the roller for forming the bent portions even though the roller has a straight cylindrical surface, no damage occurs to the conductive-pattern layers 25, the same as in the case of the above-mentioned first embodiment. - Although in the above embodiment the recessed
portion 39 is formed by means of etching, the recessedportion 39 may instead be formed by means of press forming as shown in FIG. 8D. By using press forming, the recessedportion 39 can be formed even if the thickness of thespring arm 1 is very slight or the total thickness of the insulatinglayers portion 39 may be formed so that anentire length 25L of straight portions of the conductive-pattern layers 25 is embedded in the recessedportion 39. - A description will now be given, with reference to FIGS. 9A and 9B, of a third embodiment according to the present invention. FIG. 9A is a perspective view of a third embodiment of a magnetic head suspension unit according to the present invention; FIG. 9B is a cross sectional view taken along a line b-b of FIG. 9A.
- In the present embodiment,
portions 25 r of the conductive-pattern layers 25, corresponding to the elastic portion R which generates an elastic force, are wider than other portions of the conductive-pattern layers 25. That is, a width C1 of each of theportion 25 r of the conductive-pattern layers 25 within the elastic portion R is widened over a length L corresponding to the elastic portion R. The total thickness of the conductive-pattern layers 25 and insulatinglayers portions 25 r of the conductive-pattern layers 25. Aroller 35 having a straight cylindrical surface is pressed over the entire width of the elastic portion R so as to bend the elastic portion R. - If the conductive-pattern layers25 or the insulating
layer 30 in the elastic portion R are protruded as shown in FIG. 6B, the pressing force exerted by theroller 35 is concentrated onto the conductive-pattern layers 25. However, in the present embodiment, the pressing force is dispersed onto the entire width of the widened conductive-pattern layers 25, and thus damage or breakage of the conductive-pattern layers 25 is prevented. Additionally, even if damage such as a cracking of portions of the conductive-pattern layers 25 occurs, other portions of thelayers 25 which are not damaged, resulting in reliable electric continuity. In the present embodiment, the width c1 of each of theportion 25 r of the conductive-pattern layers 25 is 2.0 mm, and the length L is 1.5 mm. - A description will now be given, with reference to FIG. 10, of a fourth embodiment according to the present invention. FIG. 10 is a perspective view of a fourth embodiment of a magnetic head suspension unit according to the present invention.
- In the present embodiment, zigzagging conductive-pattern portions25 z of the conductive-pattern layers 25 within the elastic portion R are formed to extend in a direction oblique to a direction in which other portions of the conductive-pattern layers 25 extend. Preferably, U-turn
portions 25 c are formed with a width greater than other portions. As a result, in the present embodiment, pressing force is dispersed over the contacting area of the roller to be pressed, thus reducing damaging and breakage of the conductive-pattern layers 25. - A description will now be given, with reference to FIGS. 11A and 11B, of a fifth embodiment of the present invention. FIG. 11A is a perspective view of a fourth embodiment of a magnetic head suspension unit according to the present invention; FIG. 11B is an enlarged partial cross sectional view taken along a line b-b of FIG. 11A.
- In the present embodiment, a plurality of
dummy patterns 25 d are formed within the elastic portion R. Thedummy patterns 25 d have the same construction as the conductive-pattern layers 25. When the elastic portion R is pressed by theroller 35 as shown in FIG. 11B, the pressing force is dispersed onto thedummy patterns 25 d, and thus damage and breakage of the conductive-pattern layers 25 is prevented unlike in the case of the conventional conductive-pattern layers in which the pressing force is concentrated onto the conductive-pattern layers. - FIG. 12A is a perspective view of a sixth embodiment of a magnetic head suspension unit according to the preset invention; FIG. 12B is an enlarged partial cross sectional view taken along a line b-b of FIG. 12A; FIG. 12C is an enlarged partial cross sectional view taken along a line c-c of FIG. 12C. In the sixth embodiment, a protecting layer is formed over portions of the conductive-pattern layers25 in the elastic portion R. The protecting layer comprises a
conducting layer 37 and an insulatinglayer 38. - In order to make the present embodiment, a copper base layer is formed on the insulating
layer 30 in the process shown in FIG. 6B-3-6. Theconductive layer 37 made of copper is then formed by means of electro plating, and thelayer 37 is patterned. Polyimide resin is coated over theconductive layer 37 so as to form the insulatinglayer 38. Preferably, the insulatinglayer 30 formed over the conductive-pattern layers 25 is formed with a relatively great thickness so that the insulatinglayer 30 can be flattened and smoothed by means of surface polishing. Theconductive layer 37 has a relatively large width B to cover the conductive-pattern layers 25, and has a length C which covers the length of the elastic portion R as shown in FIG. 12A. - In the present embodiment, the
roller 35 exerts a pressing force onto theconductive layer 37 which has a relatively high strength, and thus the pressing force is uniformly dispersed onto theconductive layer 37. Accordingly, damage to the conductive-pattern layers 25 is prevented when thespring arm 1 is bent by theroller 35. - FIG. 13A is a perspective view of a seventh embodiment of a magnetic head suspension unit according to the present invention. In the seventh embodiment, extra conductive-pattern layers25 s are formed. The extra conductive-pattern layers 25 s are formed along each of the conductive layers 25. Both ends of each of the additional conductive-pattern layers 25 s are connected to the ends of the respective conductive-pattern layers 25 at corresponding
connection parts pattern layer 25 s serves the same function as the damaged conductive-pattern layer 25. Therefore, a reliable connection can be realized. - FIG. 13B is a variation of the seventh embodiment according to the present invention. In this variation, each of the conductive-pattern layers25 has two paths along the straight portion thereof within the elastic portion R. One of the paths serves as the extra conductive-
pattern layer 25 s. - In all the above-mentioned embodiments and variations thereof, although the bent portions are formed by a press method using a roller, other method using a mold press or laser may be used.
- Since the
spring arm 1 according to the above-mentioned embodiments is mounted on a member of the magnetic head positioning mechanism, as shown in FIG. 2, the magnetic disk drive can reliably transmit recording/reproducing signals through the spring arm. - A description will now be given, with reference to FIG. 14 and FIG. 15A and 15B, of an eighth embodiment according to the present invention. FIG. 14 is a perspective view of the eighth embodiment of a magnetic head suspension unit according to the present invention. In FIG. 14, parts that are the same as the parts shown in FIG. 1A are given the same reference numerals, and descriptions thereof will be omitted. FIG. 15A is a perspective view of the magnetic head h shown in FIG. 14; FIG. 15B is a cross sectional view taken along a line b-b of FIG. 15A.
- In the eighth embodiment according to the present invention, the
core slider 4 is mounted on thegimbal 3 by adhesive 42 having a high insulating effect. Thecore slider 4 may instead be directly mounted on the end 1 b of thespring arm 1. Although, in the prior art, the core slider is also mounted by adhesive having an insulating effect, the electric resistance between thecore slider 4 and thegimbal 3 is low because the adhesive layer is very thin. Accordingly, thecore slider 4 may be at the same potential, that is a ground potential, as thespring arm 1 because thespring arm 1 is grounded. If a high voltage static electricity is generated in the thin-film coil of themagnetic head element 5, the insulating layer between the thin-film coil and the magnetic pole is damaged, resulting in electric discharge between the thin-film coil and the core slider. - In the eighth embodiment, in order to obtain a high resistance between the core slider and the
gimbal 3, a thick layer of the adhesive 42 is provided. It is preferable that the adhesive 42 be a UV cure resin (ultra-violet cure type adhesive). Alternatively, epoxy resin may be used. In the present embodiment, as shown in FIG. 15A, the adhesive 42 comprises an insulating material powder 42 b mixed in adhesive medium 42 a. Accordingly, the adhesive 42 can have a high electric resistance, and is formed with a relatively great thickness, and thus the insulation between thecore slider 4 and thegimbal 3 is improved. - FIG. 16 is an exploded view of an essential part of a ninth embodiment of a magnetic head suspension unit according to the present invention. In the ninth embodiment, the
core slider 4 is mounted on thegimbal 3 or the end 1 b of thespring arm 1 via aninsulator 43. In the present embodiment, theinsulator 43 is formed by applying insulating resin such as a photoresist onto a surface of thecore slider 4. The core slider is mounted on thegimbal 3 by applying adhesive 44 onto theinsulator 43. Alternatively, as shown in FIG. 17, theinsulator 43 may be applied onto a mounting surface of thegimbal 3. - FIG. 18 is a perspective view of an essential part of a tenth embodiment according to the present invention. In FIG. 18, a magnetic head comprising the
magnetic head elements 5 and acore slider 4 i is shown. Unlike the conventional magnetic head, thecore slider 4 i is made of an insulating material such as SiO2. Accordingly, the discharge as described in relation to the conventional magnetic head can be eliminated. - FIG. 19 is an exploded view of an eleventh embodiment of a magnetic head suspension unit according to the present invention. I the present embodiment, the magnetic head suspension unit is mounted on a driving
arm 13 of the magnetic head driving mechanism via an insulatingmember 45. The insulating member has screw holes 46 into which screws for fastening the magnetic head suspension unit to the drivingarm 13 are inserted. The screws are made of synthetic resin or metal screws covered with synthetic resin. Accordingly, thespring arm 1 is insulated from the drivingarm 13, which may be grounded. Alternatively, the spacer 2 may be made of an insulating material. - In the present embodiment, since the spring arm is not electrically connected to the driving
arm 13, which may be grounded, no electric discharge occurs between thecore slider 4 and the magnetic pole. - FIG. 20A is a perspective view of a spring arm of a twelfth embodiment of a magnetic head suspension unit according to the present invention; FIG. 20B is an enlarged cross sectional view showing a mounting structure of the core slider shown in FIG. 20A. In the present embodiment, a
gimbal 24 formed on thespring arm 1 has ahole 47 in the center thereof. As shown in FIG. 20B, thecore slider 4 is mounted on thegimbal 24 by adhesive 48 so that thehole 47 is filled with the adhesive 48. Since the hole is formed in thegimbal 24, the gimbal can be easily bent, if bending stress is applied to thegimbal 24 due to a difference in thermal expansion between the core slider and thegimbal 24. Accordingly, bending stress applied to thecore slider 4 is reduced since thegimbal 24 is bent instead of thecore slider 4. This feature is important when a thin and miniaturized core slider is used. - Variations of the
hole 47 are shown in FIGS. 21A through 21F. A plurality ofholes 47 may be provided, and each hole may have a rectangular shape. - In the present embodiment, the
hole 47 is filled with a part of the adhesive applied between thecore slider 4 and thegimbal 24, so that the strength of the adhesion between thecore slider 4 and thegimbal 24 is increased. Additionally, if the UV cure resin is used, an ultra-violet beam can be irradiated through thehole 47, which effectively cures the UV cure resin, and thus the strength of the cured UV cure resin can be improved. - It should be noted that although the
gimbal 24 is integrally formed with thespring arm 1, thegimbal 24 may be formed separately from thespring arm 1; that is, it may be fixed to thespring arm 1 by means of welding described in regard to the conventional magnetic head suspension unit shown in FIG. 1B. - FIG. 22A is a perspective view of a spring arm of a thirteenth embodiment of a magnetic head suspension unit according to the present invention; FIG. 22B is an enlarged cross sectional view of a mounting structure of the core slider shown in FIG. 22A; FIG. 22C is an enlarged cross sectional view showing a variation of the mounting structure shown in FIG. 22B. In the present embodiment, an
opening 49 is provided in thegimbal 24, into which opening the core slider is inserted. Theopening 49 is slightly larger than the outer dimension of thecore slider 4. - The
core slider 4 is mounted in a state where side faces of theslider core 4 is fixed, as shown in FIG. 22B, by adhesive 50 to the outer edge of theopening 49. Alternatively, as shown in FIG. 22C, thecore slider 4 may be formed to have a step in its side surface so that dimension L2 is larger than dimension L1. The dimension of the opening is determined to be a value between L1 and L2. The adhesive such as UV cure resin is applied to the outer edge of the opening after thecore slider 4 is inserted into theopening 49. An ultra-violet beam is, then irradiated from a direction indicated by an arrow in FIG. 22C so as to cure the UV cure resin. - In the present embodiment, since the
core slider 4 is supported at the side surfaces thereof, stress generated by thermal expansion of thegimbal 24 is lessened. Accordingly, deformation of thecore slider 4 due to the thermal expansion of the gimbal can be efficiently prevented. - It should be noted that the magnetic heads shown in FIGS. 20A and 22A are formed with an MR element formed by means of thin-film technology. Thin-film type magnetic head elements are formed on the MR element. However, the present invention is not limited to the specific magnetic head, and a conventional thin-film type magnetic head or a monolithic type magnetic head may be used.
- A description will now be given, with reference to FIG. 23, of a magnetic
head suspension unit 120 according to a fourteenth embodiment of the present invention. - FIG. 24 shows a 3.5-inch type
magnetic disk drive 1220 to which the magnetichead suspension unit 120 is applied. Themagnetic disk drive 1220 has anenclosure 1221 in which a 3.5-inchmagnetic disk 1222, ahead positioning actuator 1223 and other parts are housed. - A suspension (load beam)121 made of stainless steel is fixed to an
arm 122 of the actuator 223. Thesuspension 121 has a curvedbent portion 123 generating elasticity. In this regard, thecurved portion 123 of thesuspension 121 is also referred to as anelastic portion 123 in the following description. Thesuspension 121 has astiffness portion 24 extending from theelastic portion 123, andribs 121 a. Theelastic portion 123 provides a magnetic head slider (core slider) 135 with a load in a direction in which themagnetic head slider 135 moves and comes into contact with amagnetic disk 1222. Thesuspension 121 has a uniform thickness of, for example, approximately 25 μm, which is equal to one-third of the thickness of a suspension of a 3380-type (IBM) head suspension unit. - It is desirable that the width W1 of the
suspension 121 is made as small as possible, desirably 4 mm or less. This is because the resonance frequency of vibration of thesuspension 121 is prevented from lowering. - A gimbal125 is integrally formed in the
suspension 121 so that thesuspension 121 and the gimbal has a one-piece construction which uses a plate. The gimbal 125 includes a pair of C-shapedopenings suspension 121. Twoslits suspension 121 along respective sides of thesuspension 121. - The gimbal125 includes a magnetic
slider fixing portion 130, a first pair ofbeam portions beam portions slider fixing portion 130 has large surface dimensions enough to fix themagnetic head slider 135 thereon, and has the same dimensions as the magnetic head slider 135 (a=1.6 mm, b=2.0 mm). However, it is possible for theslider fixing portion 130 to have an area less than themagnetic head slider 135 when a sufficient adhesive strength can be obtained. - The
magnetic head slider 135 is a light weight structure type slider, which has been proposed in Japanese Patent Laid-Open Application No. 4-228157. The proposed slider has a flat back surface opposite to a disk facing surface. The flat back surface of the slider is fixed to the fixingportion 130 by means of an adhesive, which can be an insulation adhesive or an adhesive including an insulator (for example, insulator power). In this case, theslider 135 is located so that the center thereof corresponds to the center of the fixingportion 130. It is also possible to use other types of sliders. - The
beam portions portion 130 along a line (suspension width direction line) 138, which passes through the center of the fixing portion 130 (the above center is also the center of the slider 135), and crosses alongitudinal center line 137 of thesuspension 121 at a right angle. Each of thebeam portions length 11. - The
beam portion 133 extends from thebeam portion 131 towards the respective sides of thebeam portion 131 so that thebeam portion 133 crosses thebeam portion 131 at a right angle and extends parallel to theline 137. Similarly, thebeam portion 134 extends from thebeam portion 132 towards the respective sides of thebeam portion 132 so that thebeam portion 134 crosses thebeam portion 132 at a right angle and extends in parallel with theline 137. Thebeam portion 133 is joined toportions suspension 121 in the periphery of the gimbal 125. Similarly, thebeam portion 134 is joined toportions 142 and 143 of thesuspension 121 in the periphery of the gimbal 125. In other words, thebeam portion 133 extends from theportions beam portion 134 extends from theportions 142 and 143 of the gimbal 125. The distance between the center of thebeam portion 133 and one of the two ends thereof is 12. Similarly, the distance between the center of thebeam portion 134 and one of the two ends thereof is also 12. - The
beam portion 133 and thebeam portion 131 form a T-shapedbeam 139A. Similarly, thebeam portion 134 and thebeam portion 132 form a T-shapedbeam 139B. Thebeam portions portion 130, the first pair ofbeams beams suspension 121. - The
length 11 of the first pair ofbeams suspension 121. As the width W1 of thesuspension 121 is increased, the resonance frequency of a bend and twist of thesuspension 121 becomes lower, and the flying characteristics of theslider 135 are degraded. For these reasons, the width W1 cannot be increased. However, according to the fourteenth embodiment of the present invention, it is possible to increase thelength 12 of the second pair ofbeams suspension 121. The second pair ofbeams - When a waviness of the magnetic disk being rotated is present or dust adheres to the magnetic disk, the
magnetic head slider 135 is rotated in a pitching direction indicated by anarrow 144 in a state in which the first pair ofbeams beams beams beams - As indicated by an
arrow 145, themagnetic head slider 135 is rotated in a rolling direction also. At this time, bend deformations occur in thebeams beams - FIG. 25 shows a resonance mode of the first-order bend. A deformation occurs in the
elastic portion 123 formed at the root of thesuspension 121, and the first pair ofbeams beams - FIG. 26 shows a resonance mode of the first-order twist. A twist deformation occurs in the
elastic portion 123 formed at the root of thesuspension 121 in such a manner so the right and left portions of theelastic portion 123 have different heights. The beam located on the right side of the gimbal 125 is deformed so as to be formed into a convex shape facing upwards. The beam located on the left side of the gimbal 125 is deformed so as to be shaped into a convex facing downwards. When thelengths length 12 is equal to three or four times thelength 11, the rotation stiffness responses of the slider in the pitching and rolling directions become sufficiently soft and are almost the same as each other. - As shown in FIG. 23, a composite type
magnetic head 148 and fourterminals magnetic head slider 135. Themagnetic head 148 includes an MR head for reproduction and an interactive type head for recording, these heads being integrated with each other. Themagnetic head 148 is located at a rear end surface of themagnetic head slider 135 in a relative movement direction 146 with respect to themagnetic disk 1222. - As shown in FIGS. 27 and 28,
lead wires terminals lead wires 115A through 115D has a diameter of, for example, 30 μm. Thelead wires 115A-115D are laid on the side opposite to the side on which themagnetic head slider 135 is mounted, and are attached to acenter portion 36 of the fixingportion 130 by means of an adhesive 116, which can be an insulation adhesive or an insulator containing an insulator. Further, thelead wires 115A-115D extend along thelongitudinal center line 137 of thesuspension 121 towards the base portion of thesuspension 121, and are fixed thereto at two points by means of the adhesive 116. - Reference numbers117 −1, 117 −2 and 117 −3 respectively indicate a first fixing point, a second fixing point and a third fixing point at which the
lead wires 115A through 115D are fixed by means of the adhesive 116. The first fixing point 117 −1 moves in accordance with movement of themagnetic head slider 135. Hence, it is unnecessary to be concerned about the stiffness of portions oflead wires 115A through 115D between theterminals 1100A-1100D and the first fixing point 117 −1 and to provide additional lengths of thelead wires 115A-115D. In FIG. 27, such additional lengths of thelead wires 115A-115D are not provided. The distance between the first fixing point 117 −1 and the second fixing point 117 −2 is long, and the stiffness of thelead wires 115A-115B between the fixing points 117 −1 and 117 −2 little affects the rotation stiffness of the gimbal 125. - The magnetic
head suspension unit 120 has the following features. First, the rotation stiffness of the gimbal 125 is considerably small because of the characteristics of the T-shaped beams. Second, the gimbal 125 is supported at the four points 140-143, and hence, the resonance frequency of vibration of the gimbal 125 is high even when the second pair ofbeams suspension 121 can be formed so that it has a small width W1, and hence the resonance frequency of vibration of thesuspension 121 is high. Fourth, the flying stability of themagnetic head slider 135 is excellent due to the above first, second and third features. The fifth feature of themechanism 120 is such that the first pair ofbeams beams beams mechanism 120 is such that the stiffness of thelead wires 115A-115D does not affect the rotation stiffness of the gimbal 125. - As has been described above, the gimbal125 is formed so that a pair of T-shaped beams (which form an H-shaped beam) is provided with respect to the center of the gimbal 125, and hence a low rotation stiffness and a high resonance frequency are achieved. More specifically, the rotation stiffness of the
mechanism 120 becomes one-third of that of the aforementioned IBM 3380 type head suspension unit, while the resonance frequency of themechanism 120 is as high as that of the IBM 3380 type head suspension unit. As a result, it becomes possible to stably fly a compact slider having a low airbearing stiffness. - Tables 1 and 2 show characteristics of the
head suspension unit 120 according to the fourteenth embodiment of the present invention supporting a 2 mm-length slider, and the IBM 3380 type head suspension unit supporting which a 3.2 mm-length slider.TABLE 1 COMPARISON OF STIFFNESS (static characteristics by computer simulation) Stiffness 1st embodiment 3380 type pitch stiffness 1.5 grf cm/rad 9.4 grf cm/rad roll stiffness 1.5 grf cm/rad 5.1 grf cm/rad up/down stiffness 0.55 grf/mm 2.4 grf/mm equivalent weight ratio 0.74 0.72 -
TABLE 2 COMPARISON OF RESONANCE FREQUENCY (dynamic characteristic by computer simulation) Stiffness 1st embodiment 3380 type 1st bend 2.1 kHz 2.1 kHz 1st twist 2.3 kHz 2.6 kHz in-plane 8.5 kHz 5.7 kHz - In order to make the equivalent weight ratio ((supporting spring equivalent weight)/(slider weight) of the fourteenth embodiment equal to that of the IBM 3380 type mechanism, the total length of the suspension unit is short (10 mm), which is approximately half of that of the IBM 3380 type mechanism. Further, the thickness of the
suspension 121 of the fourteenth embodiment is 25 μm, which is approximately one-third of that of the IBM 3380 type mechanism. - Table 1 shows data obtained by computer simulation. More specifically, Table 1 shows the pitch stiffness and roll stiffness of the gimbal125 of the fourteenth embodiment, and the up/down stiffness of the
suspension 121 thereof. Further, Table 1 shows the pitch stiffness and the roll stiffness of the gimbal of the IBM 3380 type mechanism, and the up/down stiffness of the suspension thereof. It can be seen from Table 1 that the rotation stiffness equal to one-third of the gimbal of the IBM 3380 type mechanism can be obtained by optimizing the width and length of the grooves in the gimbal 125. - Table 2 shows the resonance frequencies of the fourteenth embodiment and the conventional IBM 3380 type mechanism obtained by a computer simulation. The resonance frequencies of the fourteenth embodiment are similar to those of the IBM 3380 type mechanism.
- As will be seen from the above, the magnetic head suspension unit according to the fourteenth embodiment of the present invention has a low stiffness and a high resonance frequency.
- A description will now be given of a fifteenth embodiment of the present invention. In the following description, parts that are the same as those shown in FIG. 23 are given the same reference numbers.
- FIG. 29 shows a magnetic
head suspension unit 150 according to the fifteenth embodiment of the present invention. Themechanism 150 includes agimbal 151. Thegimbal 151 is formed so that the gimbal 125 shown in FIG. 23 is rotated about thecenter 136 by 90°. Two T-shapedbeams 152 and 153 are arranged in the longitudinal direction of thesuspension 121. - FIG. 30 shows a magnetic
head suspension unit 160 having agimbal 161 according to a sixteenth embodiment of the present invention. Thegimbal 161 has the aforementioned first pair ofbeams beams 33A and 34A. Thebeam 133A and thebeam 131 form an acute angle α. Similarly, thebeam 134A and thebeam 132 form an acute angle equal to the acute angle α. With the above structure, it becomes possible to form, without increasing the width W1 of thesuspension 121, the second pair ofbeams beams suspension 121. Hence, the rotation stiffness of thegimbal 161 is less than that of the gimbal 125 shown in FIG. 123. Thus, themagnetic head slider 135 in the sixteenth embodiment can be more stably flied than that in the fourteenth embodiment shown in FIG. 23. - FIG. 31 shows a magnetic head suspension unit170 having a
gimbal 171 according to a seventeenth embodiment of the present invention. Amagnetic head slider 135A of the mechanism 170 includesflanges slider fixing portion 130A of thegimbal 171 includes anopening 174 having a size corresponding to themagnetic head slider 135A. Theopening 174 is of a rectangular shape defined by arectangular frame 176. As shown in FIG. 31, themagnetic head slider 135A engages theopening 174, and theflanges frame 176 by means of an insulation adhesive or an adhesive containing an insulator. In this manner, themagnetic head slider 135A is fixed to the magnetic headslider fixing portion 130A. - As shown in FIG. 32, the center G of gravity of the
magnetic head slider 135A is substantially located on the surface of thesuspension 121. Hence, in a seek operation, themagnetic head slider 135A is moved by exerting a force on the center G of gravity. Thus, an unnecessary rotation force about the center G of gravity of themagnetic head slider 135A does not occur, and the unbalance of themagnetic head slider 135A is reduced. As a result, themagnetic head slider 135A can stably fly in the seek operation. - Further, the height of the magnetic head assembly can be reduced. Hence, it is possible to laminate layers of the head at reduced intervals and to provide an increased number of disks per unit length. As a result, it is possible to increase the volume storage density of the magnetic disk drive and hence the storage density.
- FIG. 33 shows a magnetic
head suspension unit 180 having amagnetic head slider 135B according to an eighteenth embodiment of the present invention. Themagnetic head slider 135B has aflange 181 formed around the circumference thereof. Themagnetic head slider 135B engages theopening 174, and theflange 181 is adhered to the magnetic headslider fixing portion 130A by means of an adhesive which can be an insulation adhesive or an adhesive containing an insulator. That is, the eighteenth embodiment of the present invention differs from the seventeenth embodiment thereof in that the whole circumference of themagnetic head slider 135B is made to adhere to the fixingportion 130A. Hence, the adhesive strength is increased and the reliability of the magnetic head suspension unit is improved. - FIG. 34 shows a magnetic
head suspension unit 190 according to a nineteenth embodiment of the present invention. FIG. 35 shows a free end of a suspension of the magnetichead suspension unit 190. Themechanism 190 is designed so that it does not have any influence of the stiffness of lead wires, which affect flying of the slider having a low airbearing stiffness. For example, when, in the case where four lead wires are connected between the slider and the suspension (see FIG. 27), each of the lead wires has a diameter of 30 μm and has an additional length (free length) of 1 mm, the rotation stiffness of the gimbal is approximately five times that of the gimbal in which there is no lead wire. This degrades the flying stability of the slider. - The magnetic
head suspension unit 190 haswiring patterns suspension 121 in the longitudinal direction. Each of the wiring patterns 191-194 is approximately 5 μm thick and 50 μm wide. The thickness and width of the wiring patterns depend on the resistance of the conductive pattern and the capacity of thesuspension 121. -
Terminals 195A-195D made of copper are formed on the base portion of thesuspension 121. Further,terminals 196A-196D are formed in aterminal area 130 a of the magnetic headslider fixing portion 130 of the gimbal 125. The tops of theterminals 195A-195D and 196A-196D are plated by, for example, Au. This plating contributes to preventing exposure of copper and improving the bonding performance. Ends of thewiring patterns terminals wiring patterns beams terminals wiring patterns beams terminals - As shown in FIG. 36, the
wiring patterns suspension 121 by means of an insulatingfilm 197, and are covered by aprotection film 198. The insulatingfilm 197 and theprotection film 198 are made of photosensitive polyimide and are grown to a thickness of approximately 5 μm. The insulatingfilm 197 and theprotection film 198 are respectively patterned by the photolithography technique. The thickness of the insulatingfilm 197 is determined on the basis of a capacitance between the conductive pattern (made of Cu) and the suspension (made of stainless steel). - As will be described later, polyimide has heat-resistance enough for an annealing process. Since polyimide has photosensitivity, it can be easily patterned. Further, the
polyimide films - It is likely that the
terminals 195A-195D and 196A-196D are etched because these terminals are not covered by theprotection film 198. In order to prevent theterminals 195A-195D and 196A-196D from being etched, the surfaces of these terminals are covered by an Au film (not shown) having a thickness of approximately 1 μm formed by plating or vapor deposition. - As shown in FIG. 37, the
magnetic head slider 135 is made to adhere to the fixingportion 130 by means of an adhesive which can be an insulation adhesive or an adhesive containing an insulator. Theterminals 196A-196D are located at a right angle with respect toterminals 1100A-1100D of themagnetic head 148 formed on the end surface of themagnetic head slider 135, and are respectively connected to theterminals 1100A-1100D by means ofAu balls 1101A-1101D. TheAu balls 1101A-1101D are formed by means of, for example, a gold ball bonding device. In order to facilitate bonding, theterminals 196A-196D andterminals 1100A-1100D are located as shown in FIG. 37. In order to facilitate a crimp operation on theAu balls 1101A-1101D, theterminals 1100A-1100D are long in the direction of the height of themagnetic head slider 135 and are located so that theseterminals 1100A-1100D face theterminals 196A-196D in the state where thehead slider 135 is fixed to the fixingportion 130. - In addition to FIG. 37, FIGS.55-59 illustrate an embodiment with a bonding ball connection in more detail.
- FIG. 55 is a structural diagram of a magnetic disk apparatus to which another embodiment of the present invention directed to bonding balls is adapted, FIG. 56 is a cross section of the structure in FIG. 55, FIG. 57 is a front view of an actuator in FIG. 55, FIG. 58 is an explanatory diagram of the seventeenth embodiment of this invention in FIG. 55, and FIG. 59 is a diagram for explaining how to connect the embodiment.
- FIG. 55 illustrates a magnetic disk apparatus which allows a head to float onto a magnetic disk to execute magnetic recording.
- Provided on a base60-1 of the apparatus are a 3.5-in magnetic disk 5-1, which rotates around a spindle shaft 64-1, and a magnetic circuit 63-1. An actuator 4-1 is mounted rotatable around a rotary shaft 62-1.
- A coil41-1 is provided at the rear portion of this actuator 4-1, as shown in FIGS. 59, 56 and 57, and the coil 41-1 is located in the magnetic circuit 63-1.
- As shown in FIG. 56, nine arms3-1 are formed at the front portion of the actuator 4-1, each arm 3-1 are formed at the front portion of the actuator 4-1, each arm 3-1 provided with support plate (suspension) 7-1 which has a magnetic head core (core slider) 8-1 provided at the distal end.
- This actuator4-1, together with the coil 41-1 and magnetic circuit 63-1, form a linear actuator. When current flow through the coil 41-1, the actuator 4-1 rotates around the rotary shalt 62-1 to move the magnetic head core 8-1 for a seek operation in a direction perpendicular to the tracks of the magnetic disk 5-1 (radial direction).
- In FIG. 58, “7-1” is a support plate (suspension) made of metal having a spring property, such as stainless. An insulating layer is coated on the support plate, and a pair of wiring patterns 71-1 and suspension connector terminals 72-1 are formed thereon by a copper pattern. The support plate 7-1 has its one end fixed to the arm 3-1 by laser spot welding or the like.
- “8-1” is a magnetic head core (core slider) which has a pair of core slider connector terminals 82-1 and a thin-film magnetic head 81-1 provided on the sides.
- When the magnetic head core8-1 is mounted on the support plate 7-1, the connector terminals 72-1 of the support plate 7-1 and the connector terminals 82-1 of the magnetic head core 8-1 are fixed with the positional relationship as shown in FIG. 58(B) and 59(A), and gold balls W about 0.1 mm in diameter are made to contact both gold-plated connector terminals 82-1 and 72-1 and are subjected to pressure bonding an ultrasonic bonding by a ball bonder, the connector terminals 82-1 and 72-1 are electrically and mechanically connected via the gold balls W due to intermetal bonding. In this example, the magnetic disk 5-1 is located upward of the diagram.
- When the support plate7-1 is provided with the wiring patterns 71-1 and connector terminals 72-1 while the magnetic head core 8-1 is provided with eh connector terminals 82-1, they can be connected by gold ball bonding. Therefor, even the minute
magnetic head core 8 can easily be connected, thus accomplishing the miniaturization of the magnetic head assembly. - Further, unlike lead wires, wiring is not necessary, so that difficult wiring at the minute suspension is unnecessary, further facilitating the assembling.
- Furthermore, the number of components is reduced to make the assembling easier and accomplish a small magnetic head assembly.
- FIG. 59(b) shows a modification of the seventeenth embodiment in which a dummy terminal 83-1 is provided at the flow-in side of the magnetic head core 8-1, and a dummy terminal 73-1 is provided on the wiring pattern 71-1 of the support plate 7-1 accordingly. With gold balls W about 0.1 mm in diameter in contact with both gold-plated connector terminals 83-1 and 73-1, pressure bonding and ultrasonic bonding are performed by a ball bonder, those connector terminals 83-1 and 73-1 are connected together via the gold balls W due to intermetal bonding.
- Accordingly, the magnetic head core8-1 has both ends connected by the gold balls W to the support plate 7-1, so that adhesion of the magnetic head core 8-1 to the support plate 7-1 is unnecessary and the connection can be made by the ball bonding step alone, further facilitating the assembly.
- Although the lead wires are connected to the arm side terminals (see FIG. 58(A)) of the wiring patterns71-1 of the support plate 7-1 before connecting to the arm 3-1 in this example, this wiring is easy because the arm 3-1 is relatively large.
- The wiring patterns191-194
bypass holes head slider 135. The hole 1102 c is used to fix thesuspension 121 to the arm 122 (not shown in FIG. 34). Theholes - As shown in FIGS. 34 and 35,
dummy patterns 1103A-1103D and 1104A-1104D are provided so that these dummy patterns are symmetrical to the bypassing portions of the wiring patterns 191-194 with respect to theholes film 197 and theprotection film 198 are provided for thedummy patterns 1103A-1103D and 1104A-1104D in the same manner as the wiring patterns 191-194. Thedummy patterns 1103A-1103D and 1104A-1104D are provided in order to balance the mechanical stiffness of thesuspension 121 in the direction of the width of thesuspension 121. - As shown in FIG. 35, the wiring patterns191-194 are arranged so that these patterns form a loop. This loop functions as an antenna, which receives noise components contained in the head signals. As the size of the loop is increased, the degree of the noise components is increased. In order to reduce the size of the loop, the
wiring patterns terminals hole 1102A and themagnetic head slider 135, and all the wiring patterns 191-194 are gathered in the vicinity of thehole 1102A. In order to balance the stiffness in the direction of the width of the suspension, thedummy patterns 1104A-1104D are formed. For the same reason as above, thedummy patterns 1103A-1103D are formed in the vicinity of thehole 1102B. - As shown in FIG. 35,
auxiliary films suspension 121. Theauxiliary films suspension 121 is clamped in a bending process which will be described later. Such a clamping force is also received by the wiring patterns 191-194. The clamping force is distributed so that the clamping force is exerted on not only the wiring patterns 191-194 but also theauxiliary films - As shown in FIGS. 34 and 35, a
convex dummy pattern 1108 is provided in order to prevent an adhesive from flowing from the fixingportion 130 when theslider 135 is fixed to the fixingportion 130 and to prevent theslider 135 from being tilted due to the thickness of the wiring patterns. More particularly, theconvex pattern 1108 is used to form a groove in which an insulation adhesive used to fix theslider 135 is saved between thepattern 1108 and theterminals 196A-196D. Further, theconvex pattern 1108 is designed to have the same height as the patterns having theterminals 196A-196D. If thedummy pattern 1108 is not used, theslider 135 will be inclined with respect to the fixingportion 130 due to the height of theterminals 194A-194D. This degrades the flying stability of the heads. Further, the use of theconvex dummy pattern 1108 increases the height of the adhesive to thus improve the insulation performance. Theconvex pattern 1108 can be formed by a cooper-plated thin film similar to the wiring patterns 191-194. Theprotection film 198 covers theconvex pattern 1108. The adhesive is provided on a step part between the wiring patterns and theconvex pattern 1108. - The
suspension 121 is produced by a process shown in FIG. 38. First, apattern formation step 1110 is performed. More particularly, photosensitive polyimide is coated on a stainless plate. The insulatingfilm 197 is formed by the photolithography technique. A copper film is formed by the plating process, the vapor deposition process or the like, and is patterned into the wiring patterns 191-194 by the photolithography technique. Thereafter, photosensitive polyimide is coated and is patterned into theprotection film 198 and theauxiliary films - Next, an etching step111 is performed in order to form the openings 126-129 and the
holes 1102A-1102C and the outward form of the suspension in the stainless plate. FIG. 39shows suspensions 1202 before punching for cutting off bridge portions (not shown) to provide pieces, so that thesuspensions 1202 are formed in astainless plate 1201 and arranged in rows and columns. - Then, a
bending step 1112 is performed by bending the respective ends of each of thesuspensions 1202 formed in thestainless plate 1201, so thatribs 121 a are formed. The bendingstep 1112 can be performed by press so that thesuspensions 1202 are processed at the same time. - Finally, an
annealing step 1113 is performed at a temperature of approximately 400° C., so that internal stress can be removed. Further, a slider adhering step and an Au bonding step can be automatically carried out before thesuspensions 1202 are punched. Hence, it is possible to automatically perform the production process shown in FIG. 38 and reduce the number of steps and the cost thereof. - The
suspension 121 can be produced without performing theannealing step 1113. In this case, as is shown in FIG. 40, thepattern formation step 1110 and theetching step 1111 are performed, and subsequently the slider adhering step and the Au bonding step are carried out. Thereafter, the bendingstep 1112 is carried out to form theribs 121 a. - As shown in FIG. 41, when interactive type heads148A and 148B for recording and reproduction are used as magnetic heads, the
magnetic head slider 135 has the aforementioned twoterminals beams dummy patterns 1210 and 1211 are provided so as to extend on thebeam suspension 121 in the direction of the width of thesuspension 121. - The magnetic
head suspension unit 190 has the following features. - First, since the wiring patterns191-194 are formed on the
suspension 121, it is not necessary to provide tubes for passing the lead wires through thesuspension 121. Hence, it is possible to prevent unbalanced force caused by the lead wires and tubes from being exerted on themagnetic head slider 135 and to stably fly themagnetic head slider 135. - Second, due to use of the
dummy patterns 1103A-1103D and 1104A-1104D, the rotation stiffness of thesuspension 121 does not have polarity. Hence, the magnetic head slider can fly stably. - Third, the crimp connection using the
Au balls 1101A-1101D enables automatic assembly and non-wire bonding between head terminals and pattern terminals. - In the aforementioned embodiments of the present invention, the beams may be curved.
- A description will now be given of a magnetic head suspension unit suitable for a more compact magnetic disk drive according to a twelfth embodiment of the present invention.
- FIG. 42 shows a back surface of a magnetic
head suspension unit 1230 according to the twelfth embodiment of the present invention. FIG. 43 shows a 1.8-inch-typemagnetic disk drive 1231 to which the magnetichead suspension unit 1230 is applied. - The
magnetic disk drive 1231 has anenclosure 1232 having almost the same dimensions as those of an IC memory card. In theenclosure 1232, provided are amagnetic disk 1233 having a diameter of 1.8 inches, and an actuator to which two sets of magnetic head suspension units are attached. Themagnetic disk drive 1231 is more compact than themagnetic disk drive 1220 shown in FIG. 3. - A
magnetic head slider 135C is made compact in accordance with light-sizing of themagnetic disk drive 1231. More particularly, dimensions a×b of themagnetic head slider 135C are 0.8 mm×1.0 mm, and are approximately one-quarter the area of themagnetic head slider 135 shown in FIG. 23. In order to stably fly the compactmagnetic head slider 135C, it is necessary to considerably reduce the stiffness without decreasing the resonance frequency, as compared with the magnetichead suspension unit 130. - A
suspension 1235 shown in FIG. 42 is made of stainless, and has a base portion fixed to anarm 1236 of the actuator 1234 (see FIG. 43). Thesuspension 1235 has a width W2 of approximately 2 mm, a length L of approximately 9 mm, and a thickness to of approximately 25 μm, and is approximately a half of the volume of thesuspension 121 shown in FIG. 23. Thesuspension 1235 is diminished, and hence the resonance frequency of bending which will be described later is high. - The
suspension 1235 is a sheet-shaped piece, and a flat plate piece to which a bending process has not been subjected. Hence, there is no problem of a bending process error which degrades the flying stability of the magnetic head slider. Thesuspension 1235 includes a suspensionmain body 1237 and agimbal 1238 located on the end side of thesuspension 1235. Thegimbal 1238 has a substantially U-shaped opening (through hole) 1239 formed in thesuspension 1235. Thegimbal 1238 includes a magnetic headslider fixing portion 1240, afirst beam 1241, asecond beam 1242, athird beam 1244, and a connectingportion 1243. - The magnetic head
slider fixing portion 1240 has a size corresponding to themagnetic head slider 135C. Thefirst beam 1241 and thesecond beam 1242 extend along respective longitudinal ends of thesuspension 1235 from the end thereof. The connectingportion 1243 extends in the direction of the width of thesuspension 1235, and connects thefirst beam 1241 and thesecond beam 1242 together. Thethird beam 1244 extends from the connectingportion 1243 to the magnetic headslider fixing portion 1240 in the longitudinal direction of thesuspension 1235. The magnetic headslider fixing portion 1240 is connected to themain body 1237 of thesuspension 1235 via thethird beam 1244, the connectingportion 1243 and the first andsecond beams suspension 1230 can be reduced to a small value due to bending of the entire beams. - As shown in FIG. 42,
holes main body 1237 of thesuspension 1235. Adjustment slits 1248 and 1249 are used to reduce the rotation stiffness of the suspension. Theholes connectors 195A-195D, 196A-196D and the wiring patterns 191-194 are formed symmetrically with respect to the longitudinal direction of thesuspension 1235. Themagnetic head slider 135C is made to adhere to the fixingportion 1240, and theterminals 196A-196D and 1100A-1100D are respectively connected to each other by means of Au balls, as in the case shown in FIG. 37. - The structure shown in FIG. 42 does not use dummy patterns because the length and the width of the
suspension 1235 are less than those of the suspension shown in FIG. 34 and the loop formed by the wiring patterns is smaller than that shown in FIG. 34. However, it is preferable to arrange the wiring patterns and provide the dummy patterns as shown in FIGS. 34 and 35 in order to reduce the noise from the heads. - As shown in FIGS. 44A and 44B, the free end of the
arm 1236 is bent so that a substantially V-shaped cross section of thearm 1236 is formed in which the “V” is inverted. The free end of thearm 1236 has anupward slant portion 1236 a and adownward slant portion 1236 b declined at an angle θ with respect to the horizontal direction. - The
magnetic disk drive 1231 uses two magnetichead suspension units 1230 so that the singlemagnetic disk 1233 is sandwiched between themechanisms 1230. As shown in FIG. 45, thesuspension 1235 causes themagnetic head slider 135C to come into contact with themagnetic disk 1233 when themagnetic disk 1233 is not being rotated. At this time, themain body 1237 of thesuspension 1235 is caused to be bent and elastically deformed. The elastic force stored in themain body 1237 of thesuspension 1235 generates a load F1, which urges themagnetic head slider 35C towards themagnetic disk 1233. - Since the
arm 1236 is bent in the form of the inverted “V”, a wide gap 1250 can be formed between anend 1236 c of thearm 1236 and themagnetic disk 1233, as compared with a case indicated by a two-dot chained line in which thearm 1236 is simply bent downwards. - A description will now be given of a moment exerted on the
magnetic head slider 135C by means of thesuspension 1235 when the suspension is loaded on the disk. As shown in FIG. 46, themain body 1237 of thesuspension 1235 and thethird beam 1244 are bent. Hence, a moment is exerted by a center 1251 of themagnetic head slider 35C. A moment M1 directed counterclockwise is exerted by the suspensionmain body 1237 and the first andsecond beams third beam 1244. The dimensions of thesuspension 1235 are selected so that the moments M1 and M2 are balanced. For example, thesuspension 1235 is 9 mm long, and thegimbal 1238 is 2.5 mm long. Further, the length and width of themain body 1235 of thesuspension 1237 are 5.7 mm and 2 mm, respectively. With the above structure, it is possible to stably fly themagnetic head slider 135C. - A description will now be given, with reference to FIG. 42, of pitching and rolling of the
magnetic head slider 135C. - (1) Pitching
- The
magnetic head slider 135C is rotated in the pitching direction indicated byarrow 144 in such a manner that the first, second andthird beams main body 1237 are bent. At this time, all thebeams gimbal 1238 is bent and hence the suspensionmain body 1237 is bent. Hence, the pitch stiffness can be greatly reduced. - (2) Rolling
- The
magnetic head slider 135C is rotated in the rolling direction indicated byarrow 145 in such a manner that the first andsecond beams main body 1237 is twisted. At this time, thegimbal 1238 is bent and hence the suspensionmain body 1237 is bent. Hence, the rolling stiffness can be greatly reduced. - A description will now be given of the first-order bend and the first-order twist of the magnetic
head suspension unit 1230 obtained when the suspension is vibrated. - (1) First-order bend
- The
suspension 1235 is bent and deformed, as shown in FIG. 47. More specifically, the suspensionmain body 1237, and the first, second andthird beams gimbal 1238 are bent as shown in FIG. 45. Theoverall suspension 1235 is formed flexibly, but the resonance frequency of the first-order bend is high, while the stiffness is small. - (2) First-order twist
- The
suspension 1235 is twisted as shown in FIG. 48. Thegimbal 1238 is deformed and hence thesuspension m body 1237 is deformed. Hence, theoverall suspension 1235 is flexibly formed, but the resonance frequency of the first-order twist is high while the stiffness thereof is low. - Tables 3 and 4 show characteristics of the magnetic
head support mechanism 1230 according to the twelfth embodiment of the present invention and the magnetichead suspension unit 130 of the fourteenth embodiment thereof shown in FIG. 23.TABLE 3 COMPARISON OF STIFFNESS (static characteristics by computer simulation) Stiffness 7th embodiment 1st embodiment pitch stiffness 0.44 grf cm/rad 1.5 grf cm/rad roll stiffness 0.24 grf cm/rad 1.5 grf cm/rad up/down stiffness 0.36 grf/mm 0.55 grf/mm equivalent weight ratio 0.76 0.74 -
TABLE 4 COMPARISON OF RESONANCE FREQUENCY (dynamic characteristics by computer simulation) Stiffness 7th embodiment 1st embodiment 1st bend 1.6 kHz 2.1 kHz 1st twist 4.4 kHz 2.3 kHz in-plane 7.1 kHz 8.5 kHz - More particularly, Table 3 the pitch stiffness, the roll stiffness, and the up/down stiffness of the
suspension 1235 obtained by means of a computer simulation. It can be from Table 3 that the pitch stiffness and the roll stiffness of the twelfth embodiment of the present invention are approximately one-quarter of those of the fourteenth embodiment thereof. - Table 4 shows the resonance frequencies of the fourteenth and twelfth embodiments of the present invention obtained by a computer simulation. It can be seen from Table 4 that the first-order bend resonance frequency, the first-order twist resonance frequency and the lateral resonance frequency are kept very high.
- It can be seen from Tables 3 and 4 that the magnetic
head suspension unit 1230 according to the twelfth embodiment of the present invention has a resonance frequency as high as that of the magnetichead suspension unit 130 according to the fourteenth embodiment, and stiffness much less than that of themechanism 130. Hence, the compactmagnetic head slider 135C can be stably flied. - In an alternative of the suspension, the base portion of the
suspension 1237 is bent, so that the suspension is supported in the same manner as shown in FIG. 23 and the load F1 shown in FIG. 45 is obtained. In this case, only portions 1255 and 1256 outside of the slits 1248 and 1249 are bent. Hence, unnecessary strain is not exerted on the wiring patterns 191-194 located between the slits 1248 and 1249. - A first variation of the
gimbal 1238 of thesuspension 1235 will be described. Agimbal 1238 −1 shown in FIG. 49 has afirst beam 1244 −1 having a long width A, and anopening 1239 −1 having a long length B. First andsecond beams - FIG. 50 shows a
second variation 1238 −2 of thegimbal 1238. Thegimbal 1238 −2 has first andsecond beams - FIG. 51 shows a
third variation 1238 −3 of thegimbal 1238. Thegimbal 1238 −3 has first andsecond variations - FIG. 52 shows a
fourth variation 1238 −4 of thegimbal 1238. Thegimbal 1238 −4 has afourth beam 1260 connecting the center of the end of the magnetic headslider fixing portion 1240 and the suspensionmain body 1237 together. Thefourth beam 1260 functions to prevent a deformation of the magnetic headslider fixing portion 1240, but increases the rotation stiffness. Hence, it is desired that the width of thefourth beam 1260 be as small as possible and the length thereof are as long as possible. - FIG. 53 shows a
fifth variation 1238 −5 of thegimbal 1238. Thegimbal 1238 −5 has first and second arch-shapedbeams - As shown in FIG. 54, a bent connecting plate1261 is fixed to an arm 1236A, and the
suspension 1235 is fixed to the connecting plate 1261. Hence, it is not necessary to subject the arm 1236A to bending stresses. - In the variations shown in FIG. 49 through132, it can be said that the
third beam 1244 shown in FIG. 42 has the same width as the fixingportion 1240 and is integrated with the fixingportion 1240. - In the fourteenth through nineteenth embodiments, the load applied to the magnetic head slider is generated by bending the spring portion of the suspension. Alternatively, it is possible to employ the arm fixing structure used in the twelfth embodiment of the present invention in which the spring portion is kept flat.
- The present invention is not limited to the specifically disclosed embodiments and variations, and other variations and modifications may be made without departing from the scope of the present invention.
Claims (7)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US09/107,010 US6341415B2 (en) | 1992-08-31 | 1998-06-30 | Method for assembling a magnetic head assembly and magnetic disk drive using bonding balls connecting magnetic head terminals to wiring terminals |
Applications Claiming Priority (15)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP4-231184 | 1992-08-31 | ||
JP23118492 | 1992-08-31 | ||
JP4-318846 | 1992-11-27 | ||
JP31884692 | 1992-11-27 | ||
US3036593A | 1993-03-17 | 1993-03-17 | |
JP08211093A JP3667354B2 (en) | 1992-11-27 | 1993-04-08 | Head slider support |
JP5-82110 | 1993-04-08 | ||
JP5-198673 | 1993-08-10 | ||
JP5198673A JP2934126B2 (en) | 1993-08-10 | 1993-08-10 | Magnetic head unit for magnetic disk drive |
US11077193A | 1993-08-23 | 1993-08-23 | |
US08/248,334 US5612840A (en) | 1993-08-10 | 1994-05-24 | Magnetic spring arm assembly including structure for preventing damage to a conductive layer resulting from bending |
US61360196A | 1996-03-11 | 1996-03-11 | |
US77455496A | 1996-12-30 | 1996-12-30 | |
US08/896,435 US6002550A (en) | 1992-01-20 | 1997-07-18 | Magnetic head assembly with ball member for electrically connecting the slider member and the suspension member |
US09/107,010 US6341415B2 (en) | 1992-08-31 | 1998-06-30 | Method for assembling a magnetic head assembly and magnetic disk drive using bonding balls connecting magnetic head terminals to wiring terminals |
Related Parent Applications (2)
Application Number | Title | Priority Date | Filing Date |
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US77455496A Continuation-In-Part | 1992-08-31 | 1996-12-30 | |
US08/896,435 Continuation-In-Part US6002550A (en) | 1992-01-20 | 1997-07-18 | Magnetic head assembly with ball member for electrically connecting the slider member and the suspension member |
Publications (2)
Publication Number | Publication Date |
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US20010016975A1 true US20010016975A1 (en) | 2001-08-30 |
US6341415B2 US6341415B2 (en) | 2002-01-29 |
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US09/107,010 Expired - Fee Related US6341415B2 (en) | 1992-08-31 | 1998-06-30 | Method for assembling a magnetic head assembly and magnetic disk drive using bonding balls connecting magnetic head terminals to wiring terminals |
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JP3667354B2 (en) * | 1992-11-27 | 2005-07-06 | 富士通株式会社 | Head slider support |
JP3656534B2 (en) * | 2000-09-12 | 2005-06-08 | Tdk株式会社 | Method for manufacturing head gimbal assembly and device for cutting connection part |
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