Hitachi Chemical Company, Ltd.

Hitachi, Ltd.

Hitachi Global Storage Technologies Japan, Ltd.

Haruhiko Kikkawa

Makoto Kaji

Jun Tanaka

Fumio Kataoka

Keiko Isoda

Hideo Hagiwara

Yasunori Kojima

Mitsumasa Kojima

Shigeo Nakamura

Issei Takemoto

Yasuo Amano

Shunichiro Uchimura

Isao Obara

Osamu Narisawa

Minoru Sugiura

A magnetic disk apparatus includes a magnetic disk on which information is stored, a magnetic head which performs writing-in and reading-out of information, a suspension which supports the magnetic head, and a suspension supporting member having a &#x3c6;-shaped hinge. The suspension is supported at a tip end of the &#x3c6;-shaped hinge and an actuator for moving the magnetic head to a predetermined position on the magnetic disk is disposed so as to bridge an open portion of the &#x3c6;-shaped hinge. The actuator is coated with a resin material.

Magnetic disk apparatus and head-supporting mechanism for the same

An actuator of a magnetic disk has a laminated construction of piezoelectric flat sheet in which there are two polarized regions separated by a non-polarized region and the polarization direction and the direction of applied magnetic fields are the same as the thickness direction of the piezoelectric flat sheet. The actuator is fixed in such a manner as to bridge the top surfaces of the suspension and suspension-supporting member of the magnetic disk, and is coated with a resin material. The actuator enables vertical vibrations and dust generation which occur in association with the movement of the supporting member to be reduced and the accuracy of head positioning to be improved.

A polyimide precursor having repeating units of the formula:

Photosensitive polyimide precursor and its use for pattern formation

Polyimide precursor, polyimide and their use

A surface-protecting film is formed on the surface of the semiconductor element of a resin-sealed semiconductor device to prevent the peeling and cracking of the sealing member used in said device, by coating on said surface a polyimide precursor composition containing a polyimide precursor having a recurring unit constitution represented by the following general formula (1) and heat-curing the coated polyimide precursor composition:

Surface-protecting film and resin-sealed semiconductor device having said film

A polyimide precursor having repeating units of the formula: ##STR1## wherein R.sup.1 is a tetravalent organic group; and R.sup.2 is a divalent diphenyl group, is excellent in image formation and particularly suitable for forming a pattern using an i-line stepper, and gives a photosensitive resin composition by imparting photosensitivity to the polyimide precursor, said photosensitive resin composition being suitable for forming surface protective films for semiconductor devices or interlaminar insulating films for multilayer wiring boards.

A surface-protecting film is formed on the surface of the semiconductor element of a resin-sealed semiconductor device to prevent the peeling and cracking of the sealing member used in said device, by coating on said surface a polyimide precursor composition containing a polyimide precursor having a recurring unit constitution represented by the following general formula (1) and heat-curing the coated polyimide precursor composition: ##STR1## wherein R.sup.1 is a trivalent or tetravalent aromatic group; R.sup.2 and R.sup.3 are each a tetravalent organic group having 4 or more carbon atoms; R.sup.4 is a bivalent organic group having 4 or more carbon atoms; X is a bivalent organic group containing at least one member selected from the group consisting of oxygen and nitrogen: Y is a monovalent organic group having 15 or less carbon atoms; n=5-100 and m=0-95 with a proviso that n+m=100; and p is 1 or 2).

Surface-protecting film and resin-sealed semiconductor device having

A polyimide precursor having repeating units of the formula: wherein R.sup.1 is a tetravalent organic group; and R.sup.2 is a divalent diphenyl group, is excellent in image formation and particularly suitable for forming a pattern using an i-line stepper, and gives a photosensitive resin composition by imparting photosensitivity to the polyimide precursor, said photosensitive resin composition being suitable for forming surface protective films for semiconductor devices or interlaminar insulating films for multilayer wiring boards.

Photosensitive resin composition containing a photosensitive polyamide

A polyimide precursor having repeating units of the formula: ##STR1## wherein R.sup.1 is a tetravalent organic group having 4 or more carbon atoms; R.sup.2 is a trivalent or tetravalent organic group having one or more aromatic rings; R.sup.3 is a monovalent organic group; A is a monovalent group showing acidity; and n is an integer of 1 or 2, is effective for preparing a highly sensitive negative-working photosensitive material developable with an alkaline aqueous solution in a short time with high resolution.

Growing community of inventors

Yokohama, Japan

Haruhiko Kikkawa