Low thermal expansion resin material and composite shaped article
AssigneesHitachi, Ltd., Hitachi Chemical Company, Ltd.
InventorsShun-ichi Numata, Koji Fujisaki, Noriyuki Kinjo, Junichi Imaizumi, Yoshikatsu Mikami
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Abstract
A resin material comprising a polyamide having as chemical structural unit at least one aromatic ring which can rotate around its molecular axis but has no flexibility at another direction, said polyimide being oriented at least at a uniaxial direction, has a low thermal expansion coefficient and can be shaped together with an inorganic material into one body to give a composite shaped article.
Claims21
A composite shaped article comprising an inorganic material bonded with a low thermal expansion resin material shaped into one body, said resin material comprising a polyimide having as chemical structural unit at least one aromatic ring which can rotate around its molecular axis but has no flexibility at another direction, said polyimide having a molecular chain oriented so as to have a substantially linear structure on a plane by stretching a film, fiber or coating of the polyimide or a precursor thereof uniaxially or biaxially with a stretcher and exhibiting a linear thermal coefficient of 3.times.10.sup.-5 to 4.times.10.sup.-7 K.sup.-1.
In a multi-layer wiring board comprising layers of a wiring insulating film and a wiring, the improvement wherein the wiring insulating film is made from a low thermal expansion resin material comprising a polyimide having as a chemical structural unit at least one aromatic ring which can rotate around its molecular axis but which has no flexibility in aother direction and which is bonded at para positions, said polyimide having a molecular chain oriented so as to have a substantially linear structure on a plane by stretching a film of the polyimide or a precursor thereof uniaxially or biaxially with a stretcher and exhibiting a linear thermal expansion coefficient of 3.times.10.sup.-5 to 4.times.10.sup.-7 k.sup.-1.
In a flexible printed circuit board comprising a substrate and a metallic wiring formed on the substrate, the improvement wherein the substrate is made from a low thermal expansion resin material comprising a polyimide having as a chemical structural unit at least one aromatic ring which can rotate around its molecular axis but which has no flexibility in another direction and which is bonded at para positions, said polyimide having a molecular chain oriented so as to have a substantially linear structure on a plane by stretching a film of the polyimide or a precursor thereof uniaxially or biaxially with a stretcher and exhibiting a linear thermal expansion coefficient of 3.times.10.sup.-5 to 4.times.10.sup.-7 k.sup.-1.
In a floppy disk comprising a base plate and an information recording layer formed on the base plate, the improvement wherein the base plate is made from a low thermal expansion resin material comprising a polyimide having as a chemical structural unit at least one aromatic ring which can rotate around its molecular axis but which has no flexibility in another direction and which is bonded at para positions, said polyimide having a molecular chain oriented so as to have a substantially linear structure on a plane by stretching a film of the polyimide or a precursor thereof uniaxially or biaxially with a stretcher and exhibiting a linear thermal expansion coefficient of 3.times.10.sup.-5 to 4.times.10.sup.-7 k.sup.-1.
A memory element comprising a semiconductor element and an alpha-ray shielding layer coated on said semiconductor element, said alpha-rays shield layer being made from a low thermal expansion resin material comprising a polyimide having as a chemical structural unit at least one aromatic ring which can rotate around its molecular axis but which has no flexibility in another direction and which is bonded at para positions, said polyimide having a molecular chain oriented so as to have a substantially linear structure on a plane by stretching a film of the polyimide or a precursor thereof uniaxially or biaxially with a stretcher and exhibiting a linear thermal expansion coefficient of 3.times.10.sup.-5 to 4.times.10.sup.-7 k.sup.-1.
Dependencies are inferred from the claim text.