Abstract: A polishing liquid comprising an abrasive grain, an additive, and water, wherein the abrasive grain includes a hydroxide of a tetravalent metal element, produces absorbance of 1.00 or more and less than 1.50 for light having a wavelength of 400 nm in an aqueous dispersion having a content of the abrasive grain adjusted to 1.0 mass %, and produces absorbance of 0.035 or more for light having a wavelength of 400 nm in a liquid phase obtained when centrifuging an aqueous dispersion having a content of the abrasive grain adjusted to 1.0 mass % for 50 minutes at a centrifugal acceleration of 1.59×105 G.

Abstract: The polishing agent of the invention comprises water, an abrasive grain containing a hydroxide of a tetravalent metal element, and a specific glycerin compound.

Abstract: The polishing agent of the invention comprises water, an abrasive grain containing a hydroxide of a tetravalent metal element, polyalkylene glycol, and at least one cationic polymer selected from the group consisting of allylamine polymers, diallylamine polymers, vinylamine polymers and ethyleneimine polymers.

Abstract: Low-thermal-expansivity polyimides have a linear rigid skeleton, so that adhesion between perfectly cured low-thermal-expansivity polyimide films is very low. On the other hand, a film of a polyimide having a flexible skeleton shows high adhesiveness even after perfect curing, so that it is possible to enhance adhesion between the low-thermal-expansivity polyimide films by interposing a polyimide having a flexible skeleton. A flexible polyimide thin film is formed as a highly adhesive film on a low-thermal-expansivity polyimide film in a half-cured state, then metallic wiring is applied thereon, followed by formation of another highly adhesive thin film in a half-cured state, and then a low-thermal-expansivity polyimide film is further formed thereon. It is possible to provide a multilayer wiring structure which has improved adhesion between the low-thermal-expansivity polyimide film and the wiring pattern layer or the substrate.

Abstract: A process of forming a patterned polyimide film includes the step of conversion of a polyimide precursor into polyimide. The improvement is imidizing the precursor by means of a chemical imidizing reagent. Typically a film of polyimide precursor is formed on a substrate, and mask which is negative with respect to the desired pattern is formed on the film. The film is contacted through the mask with a chemical imidizing reagent to effect imidization of unmasked portions, thereby forming polyimide. The mask and masked portions of the film are removed, leaving the desired polyimide pattern. High temperatures and harmful etchants can be avoided.

Abstract: An acid dianhydride complex which is characterized in anti-hydrolysis, good stability, and high solubility in an organic solvent, is prepared by a reaction of a basic organic compound having a donor number of at least 20 and being free from an active hydrogen atom in the molecule and a carboxylic dianhydride compound.

Abstract: The present invention provides a process for producing a metal-polyimide composite material such as a wiring board. In production thereof, deterioration of polyamide film due to oxidation during imidization of a polyimide precursor in contact with metal such as copper or silver can be prevented. The present invention is characterized by using a polyimide precursor having an acidic functional group which is masked. Examples of the polyamide precursor are polyamic acid epoxy adducts, amido polyamic acids, silylated polyamic acids, etc.

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.

Abstract: A method for forming a polyimide film on a substrate surface by chemical vapor deposition comprises evaporating an aromatic monomer compound having one amino group and two adjacent carboxyl groups or its derivative group, such as esters of 4-amino phthalic acid, and 4-(p-anilino) phthalic acid, thus a high strength polyimide is obtained represented by the general formula having its imide groups being unidirectionally arranged in its backbone chain: ##STR1## wherein R is nil or divalent aliphatic or aromatic group and n is an integer.

Abstract: A polyimide or polyamic acid synthesized from a diamine, which may be fluorinated, and a dianhydride of the following formula: ##STR1## where R.sub.f =perfluoroalkylene and Y.sub.1 and Y.sub.2 are independently oxy-carbonyl or thiocarbonyl.

Abstract: Disclosed is a resin encapsulated semiconductor memory device comprising a semiconductor memory element, a package encapsulating the memory element and an .alpha.-rays shielding layer made from a water-resistant aromatic polyimide polymer, interposed between the memory element and the package, the aromatic polyimide polymer having a saturated water absorption rate of 1% or less. The polyimide polymer is exemplified as the polymer having the following recurring units: ##STR1## wherein R is an aliphatic or aromatic group; R.sub.1 and R.sub.2 are independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or CF.sub.3 ; and R.sub.3 to R.sub.6 are independently a hydrogen atom, a halogen atom or an alkyl group having 1 to 4 carbon atoms. The disclosure is also concerned with resin encapsulated semiconductor devices in which the aromatic polyimide polymer of low water absorption is used as an insulating layer or passivation film.

Abstract: A 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 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.