Nitto-denko Corporation

Nitro Denko Corporation

Toshihiko Omote

Yasuhito Funada

Yasuhito Ohwaki

Hiroshi Yamazaki

Toshiki Naito

Kazumasa Igarashi

Amane Mochizuki

Hirofumi Fujii

Shigenori Morita

Hideyuki Usui

Tadao Ohkawa

Masanori Ueno

Takahiro Fukuoka

Tsuguo Yamaoka

Kenichiro Ito

Naoki Kurata

Tadao Ookawa

Atsushi Tanaka

Naotaka Kinjo

Shun-ichi Hayashi

Takeshi Asano

Yasuhisa Toujou

A substance detection sensor comprises an insulation layer () having flexibility, two electrodes (A,B) so disposed on the insulation layer as to be opposite to each other at a space therebetween and connected to an electric resistance detector, and a conductive layer () which is so formed on the insulation layer as to span the two electrodes and to be electrically connected to the two electrodes. The swelling ratio of the conductive layer () is changed according to the type and/or the quantity of a specific substance.

Substance detection sensor

Only individual piece-like flexible wiring boards produced separately and judged to be non-defective products in an inspection step in advance are mounted at regular intervals on a carrying support film to thereby obtain a TAB tape carrier. According to this method, the yield on continuous production can be improved while the step of replacing defective flexible wiring boards found by inspection with non-defective flexible wiring boards can be omitted after mounting of the flexible wiring boards. A difference in level between the respective flexible wiring boards can be prevented from being caused by the replacement, so that high connection reliability can be ensured.

Tape carrier

Electric conductor patterns having inner leads arranged at a pitch of not larger than 60 &#x3bc;m are formed on a front surface of an insulating layer of a tape carrier for TAB. A reinforcing layer of stainless steel foil is formed on a rear surface of the insulating layer so as to be extend along a lengthwise direction at opposite side edge portions in a widthwise direction of the insulating layer. Accordingly, both dimensional accuracy and positional accuracy can be improved at the time of carrying the tape carrier for TAB or at the time of mounting and bonding electronic parts though the insulating layer can be formed so as to be thin.

Tape carrier for TAB

In a junction flexible wiring circuit board used for performing junction between a suspension board for mounting a magnetic head of a hard disk drive thereon and a control circuit board for operating the magnetic head, a metal layer is formed on at least one of a surface of an electrically insulating base layer and a surface of an electrically insulating cover layer.

Junction flexible wiring circuit board

The polyamic acid of the invention can be obtained by the reaction of an acid anhydride component comprising pyromellitic anhydride and 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane with 2,2&prime;-di-substituted-4,4&prime;-diaminobiphenyls as a first aromatic diamine and any aromatic diamine component, as a second aromatic diamine, of 2,2-bis(4-aminophenoxyphenyl)propanes, 1,1-bis(4-(4-aminophenoxy)-3-t-butyl-6-methylphenyl)butane, 2,2-bis(3-amino-4-methylphenyl)hexafluoropropane and &agr;,&agr;&prime;-bis(4-aminophenyl)diisopropylbenzenes in an organic solvent. The polyimide resin of the invention can be obtained by heating such a polyamic acid solution. In the production of a circuit board, by using a photosensitive polyamic acid having a sensitizer incorporated in such a polyamic acid solution, a patterned polyimide resin layer can be provided as an insulation layer on a metal foil.

Polyamic acid, polyimide resin obtained therefrom and application thereof to circuit board

A plurality of test pieces are taken from a long-sized substrate made of stainless steel, where the test pieces are arranged in parallel to the width direction TD of the substrate in a region near the forward end of the substrate. A variation among the curvatures of the test pieces is then measured. A substrate where the variation in the curvature is 0.002 &lsqb;1/mm&rsqb; or smaller is selected as a substrate used in manufacture of magnetic head suspensions. While the selected substrate is transported in its length direction, an insulating layer and a conductor layer are stacked on the substrate to form a plurality of magnetic head suspensions.

Method for manufacturing magnetic head suspensions and method for inspecting metal substrates for magnetic head suspensions

To provide a suspension board with circuit that enables its terminals to be bonded to the other terminals with sufficient strength with simple structure, to ensure sufficient bonding reliability, the suspension board with circuit includes a suspension board , a base layer formed on the suspension board , and a conductive layer formed on the base layer and a cover layer with which the conductive layer is covered, wherein external connection terminals to be bonded to terminals of a read/write board are formed without the suspension board and/or the base layer being formed.

Suspension board with circuit

To provide a circuit board, having a circuit pattern of adequate high-frequency characteristics, for transmitting high-frequency electric signals at high speed, a circuit board, including a base layer formed of insulating material and a conductive layer formed on the base layer in the form of a specified circuit pattern, is so constructed that an air layer is made to lie between lines of wire of the circuit pattern or is so constructed that the lines of wire are covered with the cover layer but land portions of the base layer extending between the lines of wire are not covered with the cover layer. This construction of the invention enables dielectric constant between the lines of wire to be reduced and, as a result of this, the capacitance between the lines of wire can be reduced to provide improved high-frequency characteristics of the circuit pattern.

Circuit board

There are provided a circuit-forming substrate comprising a long stainless steel foil having formed on one surface or both surfaces thereof a polyimide resin layer wholly or partially, and a circuit substrate formed by using the circuit-forming substrate, wherein a conductor layer is finely patterned on the circuit-forming substrate. The circuit-forming substrate sufficiently satisfies low cost, high density and high reliability, scarcely causes warping of the substrate itself, and has excellent workability.

Circuit-forming substrate and circuit substrate

The present invention provides a circuit substrate and a circuit-formed suspension substrate comprising the circuit substrate, the circuit substrate comprising a metal foil substrate and an insulating layer composed of a polyimide resin formed on the metal foil substrate, wherein the polyimide resin is one obtained by the reaction of (A) p-phenylene diamine and (B) acid anhydrides of (a) 3,4,3&prime;,4&prime;-biphenyltetracarboxylic acid dianhydride and (b) 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane. Since a coefficient of linear thermal expansion of the polyimide resin is close to that of various metal foils, the circuit substrate causes no cracking on the resin layer and scarcely causes warpage, and the resin layer does not separate.

Circuit substrate, circuit-formed suspension substrate, and production methods therefor

In a circuit board with a conductor circuit formed on an insulating layer, a covering is formed on the conductor circuit and a terminal is connected to the conductor circuit penetrating through the covering to obtain high reliability for the connection between the terminal of the electronic component mounted on the circuit board and that of the circuit board. There is provided a level difference of 3 &mgr;m or less between the surface of the covering and that of the terminal.

Circuit board with terminal accommodating level differences

A circuit substrate having an insulating layer comprising a polyimide resin on a metal foil substrate, wherein the polyimide resin is a polyimide resin obtained by the reaction of

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Ibaraki, Japan

Toshihiko Omote