An object of the present invention is to provide a resin composition which has excellent photocurability for various active energy rays, in particular, an active energy ray including an h-line at a wavelength of 405 nm, without inhibiting photocuring reaction in an exposure step, and can confer excellent alkaline developability in a development step, when used in the fabrication of a multilayer printed wiring board; and a resin sheet, a multilayer printed wiring board, and a semiconductor device. The resin composition of the present invention is a resin composition containing: a maleimide compound (A) containing a constituent unit represented by the formula (1), and maleimide groups at both ends of the molecular chain; a photo initiator (B1) represented by the formula (2) and/or a photo initiator (B2) represented by the formula (3); and a photo initiator (C) represented by the formula (4):

##STR00001##

An aspect of the present invention relates to a resin composition containing a hydrocarbon-based compound (A) represented by the following Formula (1) [In Formula (1), X represents a hydrocarbon group having 6 or more carbon atoms and containing at least one selected from an aromatic cyclic group or an aliphatic cyclic group, and n represents an integer from 1 to 10]; and a styrenic polymer (B) that is solid at 25? C. and is different from the hydrocarbon-based compound (A).

Provided is a liquid crystal alignment layer of which a constituent member is a compound represented by the general formula (I). ##STR00001##

Provided is a liquid crystal alignment layer of which a constituent member is a compound represented by the general formula (I). ##STR00001##

Provided are (i) a solution for forming an organic semiconductor layer which solution has excellent coating property, (ii) an organic semiconductor which is produced with use of the solution and which has high heat resistance, (iii) a layer which contains the organic semiconductor, and (iv) an organic thin film transistor which exhibits high electrical properties. A composition containing: an organic semiconductor; and a polymer (1) having at least one unit selected from the group consisting of units represented by formulae (1-a), (1-b) and (1-c) given below. A composition containing the organic semiconductor, the polymer (1) and an organic solvent can be suitably used as a solution for forming an organic semiconductor layer.

Provided are (i) a solution for forming an organic semiconductor layer which solution has excellent coating property, (ii) an organic semiconductor which is produced with use of the solution and which has high heat resistance, (iii) a layer which contains the organic semiconductor, and (iv) an organic thin film transistor which exhibits high electrical properties. A composition containing: an organic semiconductor; and a polymer (1) having at least one unit selected from the group consisting of units represented by formulae (1-a), (1-b) and (1-c) given below. A composition containing the organic semiconductor, the polymer (1) and an organic solvent can be suitably used as a solution for forming an organic semiconductor layer.

An object of the present invention is to provide a resin composition and a resin sheet which have excellent photocurability for an active energy ray including an i-line with a wavelength of 365 nm in an exposure step, and can confer excellent alkaline developability in a development step, in the fabrication of a multilayer printed wiring board; and a high density printed wiring board and semiconductor device having a highly detailed resist pattern using the same. The resin composition of the present invention contains: a maleimide compound (A) containing a constituent unit represented by the following formula (1), and maleimide groups at both ends of the molecular chain; and a photo initiator (B) having an absorbance of 2.0 or more at a wavelength of 365 nm (i-line):

##STR00001##

An object of the present invention is to provide a resin composition and a resin sheet which have excellent photocurability for an active energy ray including an i-line with a wavelength of 365 nm in an exposure step, and can confer excellent alkaline developability in a development step, in the fabrication of a multilayer printed wiring board; and a high density printed wiring board and semiconductor device having a highly detailed resist pattern using the same. The resin composition of the present invention contains: a maleimide compound (A) containing a constituent unit represented by the following formula (1), and maleimide groups at both ends of the molecular chain; and a photo initiator (B) having an absorbance of 2.0 or more at a wavelength of 365 nm (i-line):

##STR00001##

The present invention aims to provide resin particles that have excellent heat resistance and that, when used as base particles of conductive particles, are applicable to mounting by thermocompression bonding at low pressure to produce a connection structure having excellent connection reliability. The present invention also aims to provide conductive particles, a conductive material, and a connection structure each including the resin particles. Provided are resin particles having a 5% weight loss temperature of 350 C. or higher, a 10% K value at 25 C. of 100 N/mm.sup.2 or more and 2,500 N/mm.sup.2 or less, and a 30% K value at 25 C. of 100 N/mm.sup.2 or more and 1,500 N/mm.sup.2 or less.

The present invention aims to provide resin particles that have excellent heat resistance and that, when used as base particles of conductive particles, are applicable to mounting by thermocompression bonding at low pressure to produce a connection structure having excellent connection reliability. The present invention also aims to provide conductive particles, a conductive material, and a connection structure each including the resin particles. Provided are resin particles having a 5% weight loss temperature of 350 C. or higher, a 10% K value at 25 C. of 100 N/mm.sup.2 or more and 2,500 N/mm.sup.2 or less, and a 30% K value at 25 C. of 100 N/mm.sup.2 or more and 1,500 N/mm.sup.2 or less.