Abstract: A method for manufacturing a product involving solder joining wherein components placed on a board on which the components are to be mounted are solder-joined to the board by subjecting the board to reflow heating under prescribed heating conditions, the method comprising: calculating, at each designated site on the board, a component volume that is occupied by the components mounted within a given area; determining the heating conditions in accordance with the calculated component volume; and performing the reflow heating based on the determined heating conditions.

Abstract: A polyimide precursor having repeating units of the formula: wherein R1 is a tetravalent organic group; and R2 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.

Abstract: 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.

Abstract: 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.

Abstract: An N-aryl-.alpha.-amino acid (I), which is a novel compound, is effective as a photoinitiator. The photoinitiator composition including this photoinitiator is effective for improving photosensitive properties of photosensitive materials containing poly(amic acid) and an addition polymerizable compound used for pattern formation. Further, a photoinitiator composition (A) comprising an N-aryl-.alpha.-amino acid (I) or (I'), a 3-substituted coumarin (II) and/or an azabenzalcyclohexanone (III), or a photoinitiator composition (B) comprising an N-aryl-.alpha.-amino acid (I) or (I'), a 3-substituted coumarin (II) and a titanocene (IV), or a photoinitiator composition (C) comprising a 3-substituted coumarin (II), a titanocene (IV) and an oxime ester (V), is effective for improving photosensitive properties of photosensitive materials containing poly(amic acid) and an addition polymerizable compound used for pattern formation.

Abstract: A photosensitive resin composition comprising (A) a polymer obtained by reacting an isocyanate compound having an ethylenic unsaturated group with a polymer which is a reaction product of a tetracarboxylic acid dianhydride and a diamine, and (B) a photoinitiator, can provide a thick film excellent in heat resistant, adhesiveness, flexibility, electrical and mechanical properties, and is particularly suitable for producing a photosensitive element.

Abstract: Disclosed herein are processes for the preparation of polyimide-isoindroquinazolinediones and precursor thereof. These polymers are useful as heat-resistant electric insulation materials, surface coating films for electronic instrument parts and especially suitable for manufacturing a photoresist. The above precursor is produced by reacting a an alkylenebistrimellitate dianhydride, a diaminoamide compound and the other amine. The precursor is readily dehydrated and ring-closed to produce polyimide-isoindroquinazolinedione, which is often conveniently conducted by producing a varnish of the precursor, applying it onto adequate substrates such as silicon wafers, glass plates, metal plates, etc. and then subjecting the coated film to dehydration. The resulting films have excellent physical properties such as good adherence, high tensile strength, low elasticity, etc.

Abstract: A polyimide obtained from a polyamide-acid or polyamide-acid ester prepared by reacting dicyclohexyl-3,4,3', 4'-tetracarboxylic acid or dinanhydride with a diamine is excellent in transparency, heat resistance and mechanical properties, said polyimide being able to be obtained at a lower temperature, and particularly suitable for an orientation film used in a liquid crystal display device.

Abstract: There are disclosed a process for producing a polyamide acid having at least one siloxane bond, which comprises carrying out the reaction of:(a) a tetracarboxylic dianhydride having at least one siloxane bond of the formula: ##STR1## wherein R represents a monovalent hydrocarbon group and m is an integer of 1 or more;(b) a diamine; and(c) a diaminoamide compound of the formula (II): ##STR2## wherein Ar represents an aromatic residue, Y represents SO.sub.2 or CO, and one amino group and Y--YNH.sub.

Abstract: A light-sensitive polymer composition comprising a poly(amic acid), a special bisazide compound and an amine compound can give a film which has high sensitivity and in which portions exposed to light are not easily released by a developing solution at the time of development.