Dynamic magnetic information storage or retrieval – Head mounting – Disk record
Reexamination Certificate
1999-02-22
2001-08-28
Klimowicz, William (Department: 2754)
Dynamic magnetic information storage or retrieval
Head mounting
Disk record
C360S244300
Reexamination Certificate
active
06282062
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a magnetic head apparatus which includes a slider with at least one thin-film magnetic head element, a resilient suspension for supporting the slider and a head IC chip.
DESCRIPTION OF THE RELATED ART
In such magnetic head apparatus, the thin-film magnetic head element for writing magnetic information into and/or reading magnetic information from a magnetic recording medium such as a magnetic disk is in general formed on the slider flying in operation above the magnetic recording medium. The slider is supported by the suspension made of a resilient thin metal plate extended from one end of a movable arm of a magnetic disk drive unit.
The head IC chip is used for amplifying writing current to the magnetic head element, for amplifying reading current from the head element and for controlling the writing and reading operations of the head element. The head IC chip had been mounted on the movable arm located in a rearward position of the suspension or on a flexible printed cable (FPC) at a rearward position of the suspension. However, if the IC chip is mounted on the movable arm or on the FPC, lead lines for electrically connecting the magnetic head element with the IC chip become long causing noises to be easily generated. Also, the long lead lines provide some delay in rising and falling times of pulse signals due to parasitic capacitance and inductance of these lead lines causing the high rate transfer of data to make difficult.
In order to suppress the generation of noises from the lead lines, Japanese patent unexamined publications nos. 53(1978)-69623, 55(1980)-150130 and 3(1991)-108120 propose magnetic head apparatuses wherein the length of the lead lines is shortened by mounting the head IC chips on the sliders or on the suspensions.
These known apparatuses can prevent noises due to the long lead lines from generation. However, if the IC chip that will have some weight is mounted on the resilient suspension, the following problems may occur.
(1) Due to the additional weight applied to the suspension, the mechanical resonance characteristics of the resilient suspension will deteriorate.
(2) Due to the additional weight applied to the suspension, some impact applied to the hard magnetic disk drive unit (HDD) provided with such magnetic head apparatus may smash the IC chip to the hard magnetic disk surface causing fracture of the IC chip itself by shock.
(3) Due to poor heat radiation ability of the suspension, the IC chip itself will be heated to a high temperature by the writing current flowing through the IC chip during recording operation.
SUMMARY OF THE INVENTION
It is therefore an object of the present invention to provide a magnetic head apparatus with a head IC chip, whereby improved mechanical impact resistance of the head IC chip can be expected.
Another object of the present invention is to provide a magnetic head apparatus with a head IC chip, whereby the mechanical resonance characteristics of the resilient suspension can be prevented from deteriorating even if the head IC chip is mounted on the suspension.
According to the present invention, a magnetic head apparatus includes a slider with at least one magnetic head element, a suspension having one end section, for supporting the slider at the one end section, a head IC chip mounted on the suspension, and a shock absorption layer for covering side surfaces and/or corner sections of head IC chip.
Since covering side surfaces and/or corner sections of head IC chip are covered by the shock absorption resin, the IC chip itself and the hard magnetic disk surface can be protected from damage such as breakage even if the IC chip hardly impacts to the disk surface due to for example drop of HDD.
It is preferred that the shock absorption layer is made of a resin material with impact resistance characteristics.
It is also preferred that the apparatus further includes an underfill layer made of a resin material with high heat conductivity, filled between the suspension and the head IC chip, and that the shock absorption layer is made of the same resin material as that of the underfill layer.
By thus filling the high heat conductivity resin material, heat generated from the IC chip can be easily dissipated through the underfill layer into the suspension to extremely improve heat radiation characteristics. In addition, the underfill layer improves not only mechanical strength of this area but also reliability of the IC chip because the underfill layer covers the bottom surface of the IC chip. Furthermore, since the shock absorption layer is made of the same resin material as that of the underfill layer, these layers can be fabricated in the same process resulting that the number of manufacturing processes can be prevented from increasing.
It is preferred that the apparatus further includes a patterned resin layer formed on a part of the suspension between a bent hinge section and a section at which the head IC chip is mounted. It is also preferred that an additional patterned resin layer is formed on a part of the suspension near its base end or a base plate. By layering such patterned resin layer on the suspension, stiffness of the suspension will increase causing the impact resistance of the head IC chip mounted on the suspension to extremely improve. In addition, since this resin layer provides a dumping effect, it is expected to extremely improve the mechanical resonance characteristics of the suspension itself.
It is also preferred that the patterned resin layer is made of a flexible resin material.
Preferably, this patterned resin layer is made of a resin material with high heat conductivity. If the patterned resin layer is made of the same resin material as that of the underfill layer, these layers can be fabricated in the same process resulting that the number of manufacturing processes can be prevented from increasing.
It is preferred that the patterned resin layer is formed on one surface of the suspension, which will oppose to a magnetic disk surface in operation. However, the patterned resin layer can be formed on the other surface of the suspension.
It is also preferred that the head IC chip is mounted on the suspension by flip chip bonding.
Further objects and advantages of the present invention will be apparent from the following description of the preferred embodiments of the invention as illustrated in the accompanying drawings.
REFERENCES:
patent: 4558510 (1985-12-01), Tani et al.
patent: 4746392 (1988-05-01), Hoppe
patent: 4760478 (1988-07-01), Pal et al.
patent: 4789914 (1988-12-01), Ainslie et al.
patent: 4891723 (1990-01-01), Zak
patent: 4991045 (1991-02-01), Oberg
patent: 5187625 (1993-02-01), Blaeser et al.
patent: 5275841 (1994-01-01), Wong
patent: 5282103 (1994-01-01), Hatch et al.
patent: 5528819 (1996-06-01), McKay et al.
patent: 5572387 (1996-11-01), Brooks, Jr. et al.
patent: 5594607 (1997-01-01), Erpelding et al.
patent: 5606477 (1997-02-01), Erpelding et al.
patent: 5668405 (1997-09-01), Yamashita
patent: 6014289 (2000-01-01), Goss
patent: 6025648 (2000-02-01), Takahashi et al.
patent: 53-69623 (1978-06-01), None
patent: 55-150130 (1980-11-01), None
patent: 3-108120 (1991-05-01), None
Patent Abstracts of Japan and JP 8-255307A, Jan. 10, 1996.
Arent Fox Kintner & Plotkin & Kahn, PLLC
Klimowicz William
TDK Corporation
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