Problem: The invention provides a polyimide precursor as well as a resin composition thereof that is excellent in coating properties of slit coating as well as productivity and also excellent in optical properties that are required for applications of flexible substrates.

Solution: The polyimide precursor comprises a structure unit derived from a fluorene backbone and a silicon-containing structure unit, and a weight-average molecular weight of the polyimide precursor is 90,000 to 250,000.

A polyimide film includes a polyimide in which a specific amount of molecular framework containing one or two silicon atoms in its main chain, wherein a total light transmittance measured in accordance with JIS K7361-1 is 85% or more; wherein a yellowness index calculated in accordance with JIS K7373-2006 is 30 or less; wherein a glass transition temperature is in a temperature range of from 150 C. to 400 C.; and wherein a tensile elastic modulus at 25 C. obtained by measuring a 15 mm40 mm test piece at a tensile rate of 10 mm/min and a chuck distance of 20 mm in accordance with JIS K7127, is 1.8 GPa or more.

An object of the present invention is to provide a curable composition which has excellent patterning properties and makes it possible to obtain a cured film having excellent light blocking properties. Another object of the present invention is to provide a cured film, a light blocking film, a solid-state imaging element, and a solid-state imaging device. The curable composition contains inorganic particles, a polymerizable compound, and a polymerization initiator, in which the inorganic particles contain metal carbide-containing particles containing a carbide of an element in group 5 of the periodic table, and a content of the metal carbide-containing particles in a total mass of the inorganic particles is equal to or greater than 55% by mass.

A solvent for a resin composition that includes a polyimide precursor having a structure unit derived from polyamic acid and a structure unit derived from siloxane having a monovalent aliphatic hydrocarbon group of 1 to 5 carbon atoms or a monovalent aromatic group of 6 to 10 carbon atoms. The solvent is a mixture of an amide-based solvent and a non-amide-based solvent having a boiling point of 160 C. or higher, and the resin composition includes cyclic siloxane.

A polyimide precursor composition according to the present invention enables alleviation of thermal expansion-contraction properties of a polyimide film resultingly prepared, by means of using siloxane-based diamine having a particular structure and a solvent having a positive partition coefficient. And the present invention enables excellent transparency, heat resistance, mechanical strength and flexibility and effective reduction of residual stress, and thus can be used in various fields such as a substrate for a device, a cover substrate for a display, an optical film, an integrated circuit (IC) package, an adhesive film, a multi-layer flexible printed circuit (FPC), tape, a touch panel and a protective film for an optical disk.

A resin composition including: (A) a polyimide resin containing 60 mol % or more of a diamine residue having a structure represented by General Formula (1) below in all diamine residues; (B) a thermosetting resin; and (C) a thermally conductive filler, wherein the resin composition contains 60 parts by volume or more of the thermally conductive filler (C) in 100 parts by volume of a total of the polyimide resin (A), the thermosetting resin (B), and the thermally conductive filler (C). Provided is a resin composition capable of providing a sheet that is excellent in heat resistance and thermal conductivity, has a low elastic modulus, and is excellent in thermal responsiveness.

##STR00001##

A photosensitive polyimide resin composition is provided. The resin composition comprises an infrared absorber, an epoxy, a photosensitive polyimide and a photo initiator. The infrared absorber includes pigment and has an amount of weight accounting for 5-40% of total solid weight of the photosensitive polyimide resin composition. The epoxy has an amount of weight accounting for 5-40% of total solid weight of the photosensitive polyimide resin composition. The photosensitive polyimide has the structure of formula (1):

##STR00001## wherein m, n are independently 1 to 600; X is a tetravalent organic group, and the main chain of X includes alicyclic structure; Y is a divalent organic group, and the main chain of Y includes siloxane structure; Z is a divalent organic group, and the side chain of Z includes phenolic hydroxyl group or carboxyl group. The photosensitive polyimide has an amount of weight accounting for 30-90% of total solid weight of the photosensitive polyimide resin composition. The photo initiator has an amount of weight accounting for 0.1-15% of total solid weight of the transparent photosensitive resin.

A method for temporary bonding workpiece includes steps as follows. A combining step is performed, wherein an adhesive layer is formed on a surface of at least one substrate and/or at least one workpiece. A bonding step is performed, wherein the substrate and the workpiece are bonded by the adhesive layer. A processing step is performed, wherein the workpiece is processed. A debonding step is performed, wherein the adhesive layer is irradiated with a laser so as to separate the workpiece from the substrate. The adhesive layer is formed by an adhesive, the adhesive includes a polymer and a light absorbing material, a content of the polymer in a solid content of the adhesive is in a range of 50 wt % to 98 wt %, a content of the light absorbing material in the solid content of the adhesive is in a range of 2 wt % to 50 wt %.

An optical member includes a laminated body configured to reduce light reflection disposed on a substrate, wherein a surface of the laminated body is a porous layer or a layer having a textured structure, and at least one layer of the laminated body is a polymer layer containing a linear polymer and a branched polymer. A method for manufacturing the optical member is also provided. The branched polymer content is 10% by weight or more and 90% by weight or less of the total weight of the linear polymer and the branched polymer. The layer having a textured structure contains crystals mainly composed of aluminum oxide.

A poly(siloxane-etherimide) composition comprising, based on the total weight of the composition, 70 to 90 wt % of a poly(siloxane-etherimide); and an additive comprising a polyester, a filler, or a combination thereof; wherein the filler comprises talc, calcium carbonate, or a combination comprising at least one of the foregoing; and wherein the composition has a number of drops to tracking at 250 volts of greater than or equal to 50 drops determined according to ASTM D-3638-85.