Abstract: In a wafer chuck for flatly vacuum-chucking a semiconductor wafer (11) supported by support pins (15) such that a pressure in a suction chamber (13) surrounded by an external wall (12), the upper surface of the external wall (12) is formed to be lower than the upper surfaces of the support pins, and the upper surface of the external wall (12) does not pressure the semiconductor wafer (11), a distance (L1) between the external wall (12) and closest support pins (15a) is up to 1.8 mm, and an alignment pitch. (L2) of the support pins (15) aligned inside the closest support pins (15a) to the external wall (12) is not more than 1.5 times of the distance (L1) between the external wall (12) and the closest support pins (15a).

Abstract: In a wafer chuck for flatly vacuum-chucking a semiconductor wafer (11) supported by support pins (15) such that a pressure in a suction chamber (13) surrounded by an external wall (12), the upper surface of the external wall (12) is formed to be lower than the upper surfaces of the support pins, and the upper surface of the external wall (12) does not pressure the semiconductor wafer (11), a distance (L1) between the external wall (12) and closest support pins (15a) is up to 1.8 mm, and an alignment pitch (L2) of the support pins (15) aligned inside the closest support pins (15a) to the external wall (12) is not more than 1.5 times of the distance (L1) between the external wall (12) and the closest support pins (15a).

Abstract: Solid copolymers are produced by copolymerizing a mixture of: (A) at least 30% by weight of a monomer having the formula: ##STR1## wherein R.sub.1 is H or CH.sub.3 and R.sub.2 is an alkyl radical containing from 1 to 14 carbon atoms; (B) from 3 to 20% by weight of an ethylenic .alpha., .beta. unsaturated carboxylic acid or anhydride thereof, or from 3 to 40% by weight of glycidyl acrylate or glycidyl methacrylate; and (C) from 0 to 67% by weight of a monomer copolymerizable with said monomers (A) and (B). Preferably, the mixture is first bulk-polymerized until conversion to the copolymer is from 10 to 80% by weight and the polymerization is completed by suspension-polymerization. Thermosetting solid coating compositions are produced by mixing a major proportion of a solid copolymer so produced with a minor proportion of a cross-linking compound or with an epoxy resin containing at least 2 epoxy radicals in the molecule in presence of a tertiary amine curing accelerator.

Abstract: Solid copolymers are produced by copolymerizing a mixture of: (A) at least 30% by weight of a monomer having the formula: ##EQU1## wherein R.sub.1 is H or CH.sub.3 and R.sub.2 is an alkyl radical containing from 1 to 14 carbon atoms; (B) from 3 to 20% by weight of an ethylenic .alpha., .beta. unsaturated carboxylic acid or anhydride thereof, or from 3 to 40% by weight of glycidyl acrylate or glycidyl methacrylate; and (C) from 0 to 67% by weight of a monomer copolymerizable with said monomers (A) and (B). Preferably, the mixture is first bulk-polymerized until conversion to the copolymer is from 10% to 80% by weight and the polymerization is completed by suspension-polymerization. Thermosetting solid coating compositions are produced by mixing and melting 60 to 95 parts by weight of the solid copolymer and 40 to 5 parts by weight of a cross-linking compound or of an epoxy resin containing at least 2 epoxy radicals in the molecule in presence of a tertiary amine curing accelerator.

Abstract: Solid copolymers are produced by copolymerizing a mixture of: (A) at least 30% by weight of a monomer having the formula: ##STR1## wherein R.sub.1 is H or CH.sub.3 and R.sub.2 is an alkyl radical containing from 1 to 14 carbon atoms; (B) from 3 to 20% by weight of an ethylenic .alpha.,.beta. unsaturated carboxylic acid or anhydride thereof, or from 3 to 40% by weight of glycidyl acrylate or glycidyl methacrylate; and (C) from 0 to 67% by weight of a monomer copolymerizable with said monomers (A) and (B). Preferably, the mixture is first bulk-polymerized until conversion to the copolymer is from 10 to 80% by weight and the polymerization is completed by suspension-polymerization. Thermosetting solid coating compositions are produced by mixing a major proportion of a solid copolymer so produced with a minor proportion of a cross-linking compound or with an epoxy resin containing at least 2 epoxy radicals in the molecule in presence of a tertiary amine curing accelerator.