Abstract: A substrate assembly including a photosensitive etching glass substrate; and a first substrate and a second substrate for interposing both main surfaces of the photosensitive etching glass substrate between them. One of the main surfaces of the photosensitive etching glass substrate is thermally bonded to the first substrate, and the other main surface of the photosensitive etching glass substrate is bonded to the second substrate. When a thermal expansion coefficient of the photosensitive etching glass substrate is defined as C0, and a thermal expansion coefficient of the first substrate is defined as C1, and a thermal expansion coefficient of the second substrate is defined as C2, C1/C2 satisfies a relation of 0.7 or more and 1.3 or less, and at least one of a relation of C0/C1 satisfying less than 0.7 or larger than 1.3, and a relation of C0/C2 satisfying less than 0.7 or larger than 1.3 is satisfied.

Abstract: A substrate assembly including a photosensitive etching glass substrate; and a first substrate and a second substrate for interposing both main surfaces of the photosensitive etching glass substrate between them. One of the main surfaces of the photosensitive etching glass substrate is thermally bonded to the first substrate, and the other main surface of the photosensitive etching glass substrate is bonded to the second substrate. When a thermal expansion coefficient of the photosensitive etching glass substrate is defined as C0, and a thermal expansion coefficient of the first substrate is defined as C1, and a thermal expansion coefficient of the second substrate is defined as C2, C1/C2 satisfies a relation of 0.7 or more and 1.3 or less, and at least one of a relation of C0/C1 satisfying less than 0.7 or larger than 1.3, and a relation of C0/C2 satisfying less than 0.7 or larger than 1.3 is satisfied.

Abstract: This invention relates to a compactingly processing method for the manufacture of spherical particles, having a heavier apparent specific gravity, of halogen-containing ethylene resin. In this method, 100 wt. parts of particles of the resin are mixed with 20-500 wt. parts of one or more of heat-resisting inorganic salts having particle sizes of 0.01-50.mu.. This mixture is subjected to a heat treatment in a gaseous phase at a temperature higher than the melting point of the resin, and then, the once added inorganic salt or salts is/are separated from the heat-treated intermediate products. In this way, the resin particles are subjected to a substantial compacting and size reduction.