PURPOSE: To prevent occurrence of blowholes in a sealing layer of low-melting point glass, by joining and fixing a crystal oscillator with and to an external supporting body through a heat-curing layer of specific polyimide type conductive paste and airtightly sealing them with the low-melting point glass.
CONSTITUTION: Leading-out sections of Ag-Au thin films 2 are formed on both surfaces of the crystal plate 1a of a crystal oscillator 1 in such a way that they are positioned at opposite sides on both sides of the crystal plate 1a, and a pair of lead frames 3 are passed through a glass-made lower case 4a and united with the lower case 4a in one body. The front end part 3a of the frames 3 corresponding to the leading-out section of the thin films 2 are joined with and fixed to the crystal oscillator 1 through a conductive heat-curing layer 5, and the lower case 4a and upper case 4b are sealed with a sealing layer 6 of low-melting point glass. The layer 5 is formed by using polyimide type conductive paste which is formed by using polyimide type conductive paste which is prepared by reacting 1∼50mol% diaminosiloxane shown by the formula, 99∼50mol diamine which does not contain any silicon atoms in the molecule, and 100mol% aromatic carboxylic acid dianhydride or its drivative simultaneously in a solvent and mixing a conductive filler with the reacted product and, therefore, occurrence of blowholes in the layer 6 can be prevented.
INOUE NAOKI
YAMAGUCHI KATSUHIKO
